I also play an off-meta spec (ele shaman) with a similar score and ilvl, and although finding groups can be a pain at times, it rarely takes more than 15 min. I think a lot of the invites are because they miss lust or necrolord though (although I get into non-Necrolord dungeons fine as well, PF and ToP are just the easiest)... it's particularly rare to get into a group with a resto shaman, and they're so popular atm.

Are you Horde or Alliance? I've long been curious about whether it may actually be easier to get into "semi-high" keys (14-16s) as Alliance (as I am) due to a lower supply of well geared/scored players than on Horde, so people sometimes have to settle for a non-optimal comp which is less of a risk on Horde.

In any case I've never seen such a restrictive M+ meta as what we have now... I thought it was a bit silly that having a rogue was borderline mandatory for much of BfA, but at least that was a single slot whereas now almost every group seems to shoot for a hunter, boomie and fire mage (or at least 2 of these).