On the RFTW.us homepage there is a tab for SHOP. That is the link to the RFTW online store. You can purchase 2020 merchandise there. If you are talking about a large bulk buyout you can select the ABOUT tab and scroll down to Board of Directors. Find the Director of Merchandise contact information located there.
You are absolutely correct in thinking that places like Gallup, Junction City, etc. may be suffering serious financial loss due to the cancellation of RFTW.
If you are interested in purchasing shirts from the wonderful locations we visit along the way I suggest that you look up the State Coordinator for that area as a starting point. They should be able to put you in contact with the local folks who may need our help.
Maybe the State Coordinators could post that contact info here on the forum and we can all try to help out.