The basis for talking about the removal of hardware acceleration are the leaks reported by news publications and additional leaks beyond those. Our own testing doesn't show a substantial reduction in performance so far. However, we have no explanation for why the initial Pixel 11 firmware had MTE completely unavailable and compiled out of the firmware. We also have no explanation for why it was partially added back in the QPR2 Beta 4 update released for the Pixel 11 yesterday which was after the release for other devices.
There's also a 2026-09-01 stable release being pushed out for the Pixel 11 despite that security bulletin not being public yet and we'll take a look to see if anything has changed in that. It's strange for there to be a regular September update at all rather than it going to QPR1 directly as expected.
Google could choose to simply communicate publicly or to answer basic questions when asked. Instead, we're having to figure out what's going on based on leaks to us and to news organization along with our own reverse engineering work. The leaks indicate there are performance regressions and that hardware support was dropped or partially dropped. It clearly wasn't fully dropped because MTE is there in hardware and while it's still force disabled in the QPR2 Beta 4 release from yesterday, we did an override on that by ignoring the kernel parameter disabling it so we could test it. As far as we can tell so far, the feature is functional. We haven't run a huge MTE test suite with all kinds of memory allocation, threads, etc. because we don't have access to one. It may be there are serious CPU errata for MTE. There's no information from Google about it beyond the leaks which are turning out to not match what we're seeing with our testing.