The current version of Lightroom Classic isn’t even designed for M1 Macs, it’s an Intel version that is only able to run on an M1 Mac through Rosetta translation.
Some fundamental technical aspects of applications like Lightroom Classic are simply not supported on iOS regardless of processor, and Apple does not provide any way to install macOS on an iPad. That’s why the only version that runs on iPad is cloud Lightroom (not Classic) on iPad OS. If anything changes about that, it will depend on Apple expanding what iOS supports. The soonest we might hear about that is if Apple announces sufficiently radical changes to iPad OS (or much less likely, iPad support for running macOS) at Apple WWDC on June 7.
Many people hope that Apple giving the iPad an M1 and up to 16GB RAM indicates some kind of big shift coming in what Apple will let an iPad do, but we won’t know what that is until WWDC.