Same expectation (Mac Pro last supported by MacOS-16 (late-2025), +1 year feature updates, +2 year security updates, final update in 2028) but different logic. Even when Apple wants to get rid of a product they've never excluded a product from new version of MacOS for models less than 3 years out from discontinuation (or less than 4 years from introduction, but the latter doesn't apply here).
The 2005 G5 Power Macs, discontinued 3rd-quarter 2006, were dropped from Snow Leopard (release 3rd-quarter 2009).
Similarly the 2013 Mac Pro, discontinued 4th-quarter 2019, was dropped from Ventura (release 4th-quarter 2022).
If Apple had managed to replace the Mac Pro on schedule in 2022 I would have expected intel support to have been dropped 2025, but with 8,1 delays and 7,1 sales/production continuing into 2023 I expect support for Intel models won't be dropped from the latest MacOS version until 2026.