SIF is stuff in face. You are right.
I think the criticism of no SIF is not about it's COVID-19 safety but more about poor scenic design choices. Basically, these complaints are shining light into Hollywood's problem of bad transitions from scene to scene. Like, I am hearing complaints of the Bride maze having beautiful scenes but then you see a Black Wallz hallway up ahead, which would have been usually covered by SIF.
It's important to know that SIF's removal is not the only change this year. There are glass dividers in some scenes protecting the actors from the guests. Halloween 4 looks to have ones that are used as Pepper's Ghost Effect (which is a added bonus). The actors in Halloween 4 also look to be aggressive behind the glass dividers.