I find it interesting that Ubuntu is testing builds with the level 3 ABI (generally 2015 onwards CPUs), even while acknowledging the value for many users of continuing to support the baseline ABI; the major "commercial" distros having already jumped to the level 2 (~2009 onwards CPUs) isn't so surprising.
That said, there's no indication that Ubuntu has taken any decision about moving from the baseline ABI and I would expect that given that the 2024.4 LTS release is only 4 months away that it will still be on the baseline ABI; the 2026 LTS release (and the non-LTS releases post 2024.4) may not be.