The fakenews media could have used it as a fake motive for the shooter, but, as Trump has emulated every deepstate player in ostensibly supporting the vax, that is unavailable as a fake motive. Without that in play, the assassination attempt is much more damaging to the deepstate.
Basically - if he were openly antivax (instead of crypto-antivax) they could have buried the motive there. "That's what you get for trying to extend the pandemic" (It probably doesn't need to make sense)
…and a “Pull Your Head Out of Your Ass-er”…