@Foofie,
All I know is you are a poster named Foofie. You asked the OP to ask his university friends in the psychology department, (presumably you meant professors or researchers, since he has described himself as middle-aged), if this sealioning is just a colloquial expression for passive aggressive behavior.
I think if you have an opinion about sealioning being a colloquial equivalent of passive aggressive, you should just state it instead of making oblique suggestions. Do you have such an opinion?