Both rides that cause the tiering are scheduled to get their capacities bumped by 50% in the next year. Based on history and the current plans/rumors the major changes in the 2010s will be:
2011: Star Tours II
2012: Tron Track
2012-2014: FLE (three new attractions, a very popular restaurant, a completely new themed area, and a completely rethemed area).
2016: Frozen, Rivers of Light (but not Frozen Rivers of Light, because then the projection system probably wouldn't work)
2017: Avatarland (but based on the weird blue people and not the cool cartoons)
2018-20: Star Wars and potentially other stuff at MGM. Hopefully.
So between 2012 and 2017 there will be two new themed "lands" at two different theme parks, and there is a good chance there will be at least one and potentially two more at MGM before the end of the decade. I'm personally not convinced the plans to expand Soarin and TSMM are the best use of resources, but they do help directly address the tiering issue.
I would argue that they didn't just refurb to keep up to date. For Star Tours, Tron Track, and the Nemo Seas they took existing ride vehicles but made new narratives and experiences. It is quite valid to prefer completely novel rides, but just treading water is, say, if they had just remastered the old Star Tours video in HD (or just adding some speakers to play sound in Space Mountain...). Even Spaceship Earth, which was closer to a straight refurb, added a whole new narration (by one of her majesty's knights of the realm no less), multiple new scenes, plused some existing scenes, added a new interactive element to the ride vehicles, and added a new post-show.
And what does count as a valid addition? Let's say the current rumors are true and Disney adds two new rides in a new Star Wars theme land to
Disneyland, that would be a waste of time and money as it would be two rides replacing two rides and not add "new or net new capacity"? This is an important point because I'm not sure the Magic Kingdom can really expand anymore. Everything new there will likely come at the expense of something that exists right now. FLE was only able to happen because of the land reclaimed from the fake ocean.
I also am not sure I understand what the major closures are for Epcot during this period. Seems like it is basically the Wonders of Life, but that went seasonal in January 2004 which was during the same period in which the transition of World of Motion to Test Track (99) and Horizons to Mission Space (03) significantly increased the number of thrill rides, Soarin opened to create a new headliner (05), Turtle Talk with Crush opened (04) and then the Seas was completely rethemed (07). I loved Cranium Commander and can respect the attitude that things should not close without a specific planned replacement. However, the WoL attractions had comically low attendance by that point and were likely hit even harder by the additions in Future World. I remember at one point Mission Space briefly gave out extra surprise fastpasses for Body Wars, which did not actually have fastpass, just to try and convince anyone to ride it.
Personally I do want something new and big in the pipeline for Epcot after Frozen, but I think the history of Epcot in this period is much more nuanced than they just close things and bring in nothing new. And since then the only major closure at Epcot without a known planned replacement hasn't even happened yet. Unless I'm forgetting something.