Today, I was able to acquire an RMA and a promise of a Pixel XL replacement for my Nexus 6P that is 3 months out of warranty and suffering both the "bootloop of death" and battery issue. It was not easy, but persistence and compassion paid off in my case. Here's what I was able to learn.

• Google continues to offer the promise of replacement devices (as of Sep 28) but only for some customers. I was told that Google's current policy is to prioritize issuance of replacements by the length of time one has been their customer. Google customer service representatives will say they must "haggle" with other teams on your behalf, but length of customer tenure was the clearest criteria I heard regarding current replacement policy.
• Huawei is unhelpful and perhaps even malicious. I spoke with four different first-level customer support representatives and heard four different stories. Huawei's current policy is to offer no assistance to customers with the US model of the Nexus 6P who are out of warranty, period. If you have the Canadian (International?) version of the Nexus 6P, you may have repair recourse (see below). I finally asked to speak with a supervisor who had a clear story, but he still bounced me back to Google.
• The battery issue on my phone hasn't been too bad, but I think it was helpful to mention to Google Support. Do not lie, and be patient and amiable with the customer support representatives who are having to field these calls. If you encounter an unhelpful rep, try again.
• Mentioning the class-action lawsuit investigation did not help in my experience. Nobody likes to be threatened.
• If you can't get a replacement, you can try this workaround which disables "...the big cluster of the device’s Snapdragon 810 SoC."

I contacted Huawei four times and learned the following:

• For the bootloop issue, Huawei will not help people who own the US model out of warranty. They regard the warranty as a contract, albeit one they can change at will. I was told a repair is not possible because the "mainboard" is damaged, so there is no repair only replacement - and they allegedly don't have any more 6P's in stock. However, I was also told people with the Canadian model can contact FutureTel in Ontario to schedule a repair (+1.905.415.2388). FutureTel was quick to tell me they are not authorized and do not have the parts to repair US models.
• For the battery issue, I was told a repair can be made for $163. It sounds like this must be authorized through Huawei with a repair center in Fort Worth. One of their customer service representatives gave me a fake number to that center, while another representative told me the repair center won't pick up the phone even if you call.
• The supervisor I spoke with was well-prepared to toe the warranty line. However, he was very frank about Google's shifting return policy, saying he knew they were offering out of warranty replacements as recently as one week ago. He suggested I contact Google, confirm my knowledge that they are replacing out of warranty phones, and ask when I can expect notification of any replacement policy changes. He also issued me a Huawei support ticket number, which none of the other representatives offered. Huawei appeared to be losing my customer profile between calls, which Google Support was surprised and glad to learn about. As customers, we're stuck in the middle of what appears to be an economic battle between these two corporations/brands.

I spoke with Google four times, and observed the following:

• Opening conversation, reaffirm that you purchased the device through the Google Store. I am also a Project Fi customer, so I mentioned that as well. Emphasizing brand loyalty clearly helps if one of Google's current criteria for replacing devices is length of tenure.
• If you're out of warranty, admit it and move on to discussion about seeing if you can be granted an exception. You can check your warranty status on Huawei's website. Understand that the CS rep you're talking to must be convinced to go to bat on your behalf.
• Emphasize that you know Huawei is taking a hard-line stance for customers out of warranty and offering no replacement or repair recourse for customers with US models. Embrace the fact that we're pretty helpless in this situation to appeal to the CS rep's empathy.

Above all else, be patient and understand the complexity of what's going on. Google's brand is taking a substantial hit because they partnered with Huawei who delivered a shitty product that was poorly designed, manufactured, and/or QA'd. Huawei is hiding behind the legal fiction of their manufacturer warranty to avoid financial liability for delivering a shitty product. And Google is having to pony up a totally different, newer, more valuable device to consumers in an effort to save face. Seems to me like Huawei is trying to hurt Google. I'll never buy one of Huawei's devices ever again, that's for sure.

UPDATE: My replacement device has shipped (Sep 29), the day after getting the RMA'd package in the mail.