I thought about adding a comment, but eventually got lazy. But you're right - I also always make a point of reminding people WD40 is not a good lubricant, so I should have added that, PSA and all.

So, for the record: in this case, I followed it up with an all-weather synthetic chain oil since the stuff I have on hand does have excellent corrosion protection and does in fact lube the bearings in my particular latch mechanism, while lasting.

Thanks for bringing that up.