I think there's definitely a shift in attitudes in general over M/M tickling. You have to remember that it wasn't that long ago (I would say 15 yrs or so) that finding M/M tickling wasn't as common as it is today. 20 years ago, it was comparatively like finding needles in haystacks.
Sites like this one, Jack's Rack (now defunct), TKLFrat and Fetlife have opened up the doors much more. YouTube now has literally many hours worth of M/M tickling material, mostly in the form of "tickling challenges." There have also been articles written providing research that straight male desires for having sex and sexual play with other straight men is definitely a thing and very normal.
All of this adds up to curious or repressed straight guys looking for other guys to tickle them coming forward in (I truly believe) growing numbers.
Very happy to help them out (post-pandemic, of course).