To be fair back in the day none of those terms were clear, and were all interchangable. The only similarity between all "bruisers" and "off tanks" and stuff was being somewhat tanky with damage. Riot has done a lot to make each class more unique, and I wouldn't go back personally. They definitely needed it.
Today Bruiser has pretty much lost all meaning, with people who are new just not knowing and people from the old days not applying it the same to all classes. I personally used it for any champion that was a primary fighter, secondary tank, but some people consider champs like Riven to be Bruisers.
Point is we should be using the new terms to avoid confusion.