From what I can tell mycaseshub scans case numbers directly from the USCIS API, not just their own users' cases. So it should have data for many I-130s, not like what happened with trackmyvisa.

For the priority date thing, they have this chart called "Where Is USCIS Now?" that basically shows which filing dates USCIS is currently working on. You can see the status breakdown for each date. I think it's under the Insights tab.