Not knowing very much about what goes on inside computers outside of knowing what I need for my specific needs, the switch to ARM has thrown me off a bit as I don't know enough about processors to make an informed decision.
For developers, apart from a minority of special cases, producing an ARM version of an app/plugin should be about as much work as the annual testing and patching for the latest version of Intel MacOS, and probably
less work than the recent switch from 32 bit to 64 bit. Lots of pundits here are confusing the issue of re-compiling an app for MacOS on ARM with the far more complex job of porting an app from MacOS to iOS (which can mean a major re-write).
Even for the "special cases" it will only usually be a very small part of the code that is Intel-specific. Developers don't lovingly and laboriously hand-craft processor-specific code for the sake of it.
The main reason for software
not to get an ARM Mac version will be that it is not actively supported - any "abandonware" will die, and if the developer is already lukewarm about supporting Mac, this could be the last straw. Frankly, though, such cases were just as likely to be killed by the next version of Intel MacOS - if they haven't already been killed by Catalina and the shift to 64 bit (...which will have cleared out a lot of the "dead wood").
...on top of that, we don't yet know how effective Rosetta is going to be at automatically translating x86 apps - I'd be surprised if it works well (if at all) with DAWs and plug-ins, but then Apple showed it
apparently running Maya and Rise of the Tomb Raider so - while skeptical - I wouldn't bet against it.
So, really, I'd approach the switch to ARM much the same way as a major MacOS upgrade - i.e. "The early worm gets the bird" - give it 6 months before shifting your main system and be prepared to lose a few older plug-ins.
Just factor that in to how urgently you need a new Mac - and bear in mind that we don't know how long it will be until the ARM replacement for the 5k iMac arrives: it could be up to 2 years (which would explain the rumors about a new Intel iMac this year). We don't even know what shape the line-up will be (I suspect, for instance, that the 5k iMac and the iMac Pro will "merge").