Those stickers have different fonts for the numerals - esp noticeable with the "3" and its spacing. I don't know Jackson and I don't care for stickers so I'd not know, but someone who does will likely recognize what is going on here rather quickly.
The date on the PSA DNA database matches the letter’s date but oddly, it does not include the grade.
I am not sure what the authentication fee was for Michael in 2009 but I would guess that they were at least $50 even before his death. If so, they would have produced a full LOA, as opposed to the cert corresponding to your first photo.