It probably depends on how small the chokes are. Moving an army through a choke that is being stormed is going to result in, collectively, way more damage to the army. It will be less damage to each individual unit, but more damage collectively. So this might combo well with a colossus that then mowes through the remainder of the health.
It’s a buff to gm zergs who don’t play viper, like Ukko. Vipers were never my favorite unit either, I still played them a lot, but I have a lot of styles designed around never making them in ZvT.
I am 95% certain microbial changes will be a massive buff to swarm host infestor styles. We’re talking about not a giga-buff, but a terra-buff. Does it cut tank damage in half vs spines? The locusts don’t take damage from tanks until landed at which point they are protected by the microbial. Locusts waves don’t move much once landed and so microbial would combo well with that. Another thing is that fungal prevents movement so the locusts don’t have to move to intercept and take half damage.