I think they assuming from the past that this will happen. When Apple moved from powerPC to x86 there was Rosetta 1. It got deprecated as well.
https://techcommunity.microsoft.com/blog/sqlserver/azure-sql...
There's probably other closed-source linux software being distributed as amd64-only binaries (rosetta 2 for linux VMs isn't limited to docker containers).
It made financial sense to stop paying the licensing fee to include it in each new version of the OS as quickly as possible.
There is no financial incentive to remove the current version of Rosetta, since it was developed in-house.