That seems to be the case, yeah. They're not looking to cram bags into the sizer, they're just looking for volunteers to gate check their bags regardless and they have a target number in mind.

From the outside the AC effort on this seems so haphazard. If they think that full bins are disrupting OTP (I feel like there are half a dozen other problems that impact OTP more, but okay) then it feels like they should be attacking the problem from several angles:

1. Avoidance. Push the .... out of "free checked bag if it is legal carryon" during the check in flow. Get the bag tracking working consistently. Make people want to not bring their rollboard to the gate in the first place.

2. Enforcement. The sizer is a red herring - if it fits in the bin wheels first (most fins) or sideways (some of the smaller fins) then trying to get people to fight with the sizer is a waste of time when there are issues that take up a lot more bin space. I'm talking about is the person who has a rollboard, laptop bag, purse, garment bag, duty free shopping bags and a phat coat ... and then stuffs 90% of that into the overhead. I had a J narrowbody flight recently where I angered someone when I rearranged a bin to get my rollboard to fit because it was already full of piles of other .... from one single person - this is a way bigger problem IMO than a rollboard that is 1/2" too big in one direction.

3. Gate Checking. If you are going to push for a fixed number of bags to check then that is fine but then you need to staff your gates accordingly. If AC has one agent trying to deal with getting people to check bags, the random pax up at the gate to ask who knows what question, clearing the onload list and trying to deal with comms around readiness for boarding ... then trying to gate check bags makes things WORSE and delays the start of boarding. You want to gate check 30 bags? Make sure you have two staff there 30-45 mins prior to boarding to start that process.