Ordinarily MacOS versions are supported for three years from release, so as a minimum I expect my Early 2015 MBP to run a supported OS (Monterey) for the next three years.
I expect Intel Macs sold today might run a supported OS for longer, but clearly we are in a moment of transition and normal rules might not apply.
I would be more worried about how long the Intel version of my Apps is going to be supported (both third party’s and Apple’s).
How soon will we see Apple release versions of their pro software (FCP, Logic) with functionality that can only run on AS?
They might support the OS and the hardware, but that means nothing if the latest version of your main software can’t (fully) run.