Well, the existing i386 port is going to remain as-is for supporting old software (especially games) (but the CPU baseline will likely get increased), it isn't going to be removed, so you would need a new architecture for 32bit-only hardware.
Since i386 is not going to do the 2038 transition either (since that would break the ABI), also you would need to either make a new ABI for the new port, or do the 2038 transition for it too.
Over time more and more 32-bit bugs will get introduced, so there will be lots of maintenance work to do too.
> ...it isn't going to be removed
I had seen conflicting information about this, though nothing official. I suppose we'll know more once some actual release planning happens for forky, which might take some time.