I was able to get around the issue by doing the following:
## create empty environment
conda create -n rstud
## activate
conda activate rstud
## use x86_64 architecture channel(s)
conda config --env --set subdir osx-64
## install rstudio-desktop
conda install rstudio-desktop
Based on information from here: Env creation from python 3.7 not working M1 Apple Silicon Mac (Miniconda 3) · Issue #12206 · conda/conda · GitHub