in the number of shapeshifer heroes has there been since
1- wand changes
2- Scion cabal closing

It looks like the last round of wand changes was May 2014 and we lost Scion in June of 2014, so for your purposes you may as well combine those into one event.

I don't have the ability to pull hard numbers, not that I'd want to spend the time on it anyway. However, you could always use PBF data (Dio's even did the hard work for you) and chart shapeshifters created before/after those events and compare.

A few thoughts:

I don't expect that the closing of Scion had big impact on level 51 shapeshifter counts since the cabal rarely had more than one at a given time and while it often had numerous (low quality) shapeshifter pledges, they typically fizzled out before hero.

We may have seem a dip in these numbers back in 2013 when we took locate away from shapeshifters, as we saw a lot of "gear locker" or "locate monkey" hero shapeshifters that did nothing but farm and hoard equipment.

It's possible there could be a correlation between the wand changes and a drop in percent of total (which is all I really care about) of mages in general or shapeshifters specifically. Even if this were the case though, I don't see it as a problem or a mark against the approach we took.

Right now, as Destuvius mentioned, 8% of the MUD are shapeshifters. 23% of the MUD are mages of some kind. Of them, shapeshifter is king.

I just haven't seen a really good shifter at hero in a while other than Hoysepsis (and maybe Nuerria?). Island used to be chock full of shifters and Scion always had at least one, often times 2, that could wreck a range.

They have dropped a bit, but are still one of the higher % of classes played.