You don't need to be part of the company to know they're not going to change a fundamental structure of the game to appease a tiny subgroup of a tiny playerbase
everything to do with logic and economic feasibility. What you're asking for is the equivalent of changing CoD's melee system into Battlefield's
It would be a massive undertaking, and very likely would break the game in terms of bugs
There's multiple things wrong with your statement.
1) Adding creatures / ideas / DLC is not changing 'fundamental structure'.
2) You have no data on how in-demand various ideas are
3) You have no data on how big the playerbase is
4) You don't know how much work it'll take, nor what EA/BW is willing to take. I will comment so far every DAI DLC has been bigger in scope than the previous, and in my opinon more 'interesting'. If we take previous ME games for an example, they do get quite interesting for DLC overall. Past performance is not indicative of future actions of course, but it is an 'interesting' ride so far for me. The nitty gritty financial details of game development also require insider knowledge I suspect very few people actually have.
A 'massive undertaking' may be acceptable with the publisher/owner's financial and game developer's approval.
And even that is more likely, since CoD has a vastly larger player base.
5) There's lots of motivations to do things far beyond the scope of your analysis. In particular for your example, actually less likely due to different ownership of IP's and lawsuits.
EA / BW will work on things so long as they're in business. If previous media blackout policy remains, they'll do so at their discretion, and with forces unbeknownst to outsiders and known only those insiders with NDA's & legal contracts. How big in scope, how 'creative', how much work it'll take, etc, will be at their discretion.
They've been hiding Dragons in MP from us for... months, probably since before new year's. I would call that a lot of work involved, and something signifigantly different than before. What's next in the pipeline, and down the future they cannot tell us (for a lot of reasons). I would not presume to know the detail of every force involved into their development. I wouldn't bet against anything right now on mere idle speculation. We just got Dragons. Golems, Demons, Barkspawn. . . Andraste's ******, who knows what's next? Only insiders, and possibly those with a vested interest (money on a large scale, usually) looking into the nitty gritty. Not casual playerbase with no actual information.