The short answer is DON'T DO IT.
I recently did this and moved 50 old TM backup folders to the Bin, and now I cannot empty the Bin (it would take days, and then might fail!). I also find I cannot PUT BACK the folders. When I try to do this, it seems not to respond and looks like it's hanging on that command.
I've also seemed to totally confuse TM. It runs but there's so much activity on the drive, and it's taking so long, I had to abandon the approach after 30 hours with only 15GB out of 745GB to backup.
After researching this wonderful community, I found a post from BennyHaHa in December 2019 who did exactly the same mistake as me. Fortunately, the community came to his rescue and this, in turn, has helped me with a plan to solve my own problem. Huge thanks to Benny and the others for that post.
I also found some great information about TM in the 'MacOS Catalina – The Missing Manual' book by David Pogue. What a great book that is and thoroughly recommended.
The community also advised me to get rid of my CleanMyMac app but I'm not so sure. Once I have my iMac back on track, it's so convenient and quick to use. I would appreciate more opinion about this advice.