I'm not saying it won't help at all, but I think air filtration solves a second or third order problem.
I.e. if you're in row 10 of an airplane and there's an infected person in row 25, the air filtration systems in the airplane do a pretty good job of protecting you. Those stories about air filtration systems are due to the belief by many that airplanes are somehow more dangerous because of recycled air, and they're putting those stories out there to defuse that belief.
If you're in 25A and there's an infected person in 25B, however, the air filtration system of the airplane never comes into play. At that point it's a lot better protocol for you both to be wearing a mask.
Likewise, in a restaurant the air filtration could help protect someone 25 feet away at a different table. But if it's 4 people from 4 households sharing a table for an hour, the air filtration doesn't even come into play.
So I'm not saying it's a bad idea. I think we'd have to look at cost, and the reduced airflow of strong filters potentially increasing the energy requirements of running the system, measured against the actual benefit provided. Especially for businesses which are now doing a lot of WFH--better spacing and air filtration could help avoid outbreaks in an office environment.
But I'm saying that if one of the primary modes of spread is small gatherings, as a lot of people are saying right now, air filtration is only a tiny piece of a much larger puzzle.