Yup, as I understand it, that's pretty much correct.
Though from your first post, I got the impression that you were aware of that and were just trying to config things so you could just use the account to surf.
As I understand things, this should still be theoretically possible - because the protocol's are all the same i.e. TCP/IP is TCP/IP is TCP/IP. AOL don't write the standards - I appreciate that you wouldn't be able to use all their proprietary stuff, because that's what won't run under linux, it's all windows based.
But even though you might be able to config things to connect to them, I suppose you then have to run the connection through all kind's of shit that are proprietary - and that's where the problem lies ??.
Never mind, as you say, when you've "got shot" of them you'll be up and running (and if things are as I understand, it should be as efficient, if not more so, and cheaper because you don't/won't want to access "their" content - which from memory isn't all it's cracked up to be).
Erm, the other minor "snag" I can think of, is that when you change provider, it could still be a little challenging to get rid of all the "AOL Stuff" that installs under windows when you install their service i.e. it wraps itself very tightly round windows, and you could still find yourself hunting out files for some time after you've uninstalled their software (unless you installed it via something that manages software installation - one of the norton utilities comes to mind - but I couldn't say for certain). Something that isn't a problem under linux, so it could be "a blessing in disguise" that aol doesnt' run under linux
good luck sorting out your new provider, see you around the forums maybe.
p.s. I've just checked another thread that was "on about AOL" and apparently, if you use an app called "Penggy" you could connect via AOL, I haven't a clue how you'd do it, and you still may want to dump them - It mightn't work, but have a surf/google for it and read the doc's if you've the time, after all, it's all good training/experience - possibly a reasonable challenge.