Possibly, depends on the frame and clearance and tyre choice.
I'm trying to work out the same but for 26 - 27.5. I reckon it will work for me due to adjustable drop outs though, if they weren't adjustable I doubt it would work.
Some of the gravel/adventure bikes will take either a fat 650b/27.5" tyre or a narrower 700c/29" tyre, something like 27.5 x 2.35" or 700c x 42mm, so you should be able to do something similar with an MTB frame.
