From my experience, sometimes BLm (and Sam) are excluded, but it's not as bad as some ppl say it is, at least for blm. I heal most of the time, but since blm is my favorite dd, I always take a look if a spot is open for it.
Speedkill groups search for the meta classes, yes. But it shouldn't be a problem to join farm groups for extreme primals or weekly kills. Usually when you can't join it's because there is already another blm or one of the other casters and ppl tend to search for 2 melees, 1 range und 1 caster. And even if you can't find a group you can simply open a new one.
However, I think it might be difficult for you to find a static as blm, if you want to search for one.