The problem with Perkins is FR is not his thing, never has been. There are plenty of authors with years of experience on the Realms who would gladly take up the torch. The Realms is basically just being used as a corporate marketing tool because of it's popularity and it's notoriety. It's fast becoming like today's music business.
What they don't seem to realize is that what made the Realms so popular is the attention to canon and history as how it tries to stay constant.
But the FR is used as the setting for stories taking place in so many different media. In the last Lore You Should Know they discussed the difficulty in determining what is canon in this environment. You have the adventure paths and setting books, the novels, the streamed games like Acquisitions Incorporated, and--soon--a movie.
To capture all of that and put it into a setting book...well, that book would have to be HUGE. Few DMs are going to want to take it on. 5e has been a great success in bringing old players like myself back into the fold and also in attracting a new generation. It does this because it offers a solid set of modern, streamlined rules that are pretty easy to pickup, yet retain an old-school flavor, and then you can buy adventure paths that make it easy to prep and play a 6-8 month campaign.
Throwing something as weighty as the realms into this doesn't seem like a good fit. I realize it would be a lot more work to create a new realm for 5e, but are there not other realms they could have brought back that would come with less baggage? Greyhawk probably would suffer from the same issue.
Seems to me that they wanted it both ways. They want a well-fleshed out campaign world with lots of cross-marketing opportunities, but at the same time, they decided to hit the reset button to force a large, well-rounded Realms peg into a tight 5e square and then say, "don't worry about making it fit, just play with it however you want!"
Which, ultimately, is what i'll do if I ever play with any of the APs set in the Realms. I will ignore nearly everything outside of the AP book and make up the rest as I need to. I would never DM for a Adventurer's League game because there is no way I'm going to be able to put in the time to know the FR as well as a fan who might play in my game.
This issue is another reason why I'm turned off by Star Wars, Star Trek, Fire Fly, LoTR, and Doctor Who rpgs. I would gladly play in them, but would never DM them.
This is also why I like to use home-brew campaigns--I don't have get into arguments about Canon with my players when it is my own world. Yeah, I probably put in as much or more work making my own world than just learning enough about FR to run games in it, but the former is a fun act of creation. The later feels like homework.