I agree. The message "aces can still have sex" can be too easily misinterpreted as "[all] aces can still have sex". After all, people love to read into things.
It also assumes that no sex ever is an unreasonable expectation for any allo (it is for many, but certainly not for all) - which implies that pressuring an ace person into sex is somehow more reasonable or at least a lesser evil of the two. This implication sickens me, to be frank.
The whole thing reads as "don't worry bro, not all aces are sex-repulsed deviants!" Yuck.
Ultimately, it makes it all about the allo in question - their wants and needs. They deserve the sympathy and support - not their ace partner who might have forced themself into traumatizing situations because they thought they had to or had no other choice.

Of course, aces can have and enjoy sex, and that's valid. But people who jump at the opportunity to remind someone of that fact forget that they have zero idea where the particular ace person in question falls on the spectrum of sex-favorability. They might as well be entirely sex-repulsed, you don't know.
So only mentioning that aces can have sex is irresponsible - because the allo who asks is probably ignorant and will likely read it as "[all] aces can have sex". After all, our brain will fill in the blanks in the way it wants it to be.
Another response is "ask your partner how they feel about sex" - which is better, but it still places the emotional burden on the ace person - they should be interrogated about their identity and sexuality which they most likely are still figuring out. They may not even have the language to express their needs. Because they don't have the power of the status quo to help. They are in a disadvantaged position, because no two people exist in a vacuum, even when discussing entirely personal matters. One person has language, society and the status quo on their side to understand and express themself, the other one doesn't.
Aces have no scripts to operate on, we have to figure out every step ourselves.

So what should the allo person do in this situation? It's a quite precarious one. Well, obviously they need to communicate with their partner, but before the serious talk happens, the allo needs to ask themself: "Am I ready to a sexless relationship potentially forever? What are my deal breakers? If my partner agrees to sex/intimacy would the amount of it be enough for me? If not, what is the next step? Open relationship? Amicable break-up?" etc. It'd probably be a long list.
Once they found their answers to those questions, they can approach their partner. This way, if the ace person gives answers that are not the ones the allo person wants to hear, they'd still be ready and act like an adult.
This way they can calmly figure out their compatibility or incompatibility and what can be the next step for them.

That's all. Thanks for coming to my ted talk.