Battlefront/Gale Force has already stated a few times that everything they sell "D&D branded" goes through rigorous approvals over at
Wizards of the Coast. It was also stated as a reason why the initial spell cards were so late--because they were waiting on WotC approvals and final text edits. I'd be surprised if any of these products weren't initially planned as an option by WotC for BM/GF9 to explore.
PS: I didn't buy the
Tyranny of Dragons screen. But I am not running that game either. I have my own home-made DM screen with a combination of full color 5E art and old school TSR logos on the player's side. I thought the look would be fun. On my side I have some useful tables from the PH and some from the
Basic D&D DM rules. I used the classic fonts from the
1E DM Screen and even printed it on goldenrod paper.

But even with that screen I have considered buying the
Elemental Evil one. Reason being that I plan on running
Princes of the Apocalypse. It is a huge $50 module and sounds like it will be a good long adventure. The screen is a cheap enough accessory and it might help some of the players get into it. I haven't totally decided yet. Mostly depends on how long it takes for them to release it. If I can get it on/before I start running
Princes of the Apocalypse the chances are much higher I would purchase it. My PCs are already approaching fifth level but definitely should be sixth or less by the time I get my hand on the adventure. I figure with bounded accuracy I can adjust the adventure up two levels in some places if needed. I am already moving it likely to the
Domain of Greyhawk on the
World of Greyhawk so some assembly will be required. I am interested in what regions of
Greyhawk the actual adventure suggests.