Was the HJA prefix the newest signatures (post-Lane/Macklem)? I haven't been keeping up with the latest prefixes because the branch I normally went to has a troublesome panhandler who appears to be aggressive, and I am very afraid to visit that branch these days.
I agree, the $100 bill has been quite abundant for many years now. Back in the 1980s, $100 bills (and $50 bills) were few and far between (back then, probably to the same extent as the $10 bill today) - there were many occurrences where I would go to the bank just after it opens, and the tellers told me they did not have any $100 bills in their tills. Because of inflation in the last 15 to 20 years (and even more this year), $100 bills are quite easy to come by. Banks probably order far more of them nowadays than 15 to 20 years ago.