I have a feeling The Lion King will outperform it. Just a gut feeling. Even that will have trouble making the top five though, with Endgame having came out, Toy Story 4, Star Wars and Frozen II on the way. That's just Disney alone. One could guess (and hope) that one of the other studios could crack the top five.
While I agree that Aladdin will have a hard time staying in the top 5 (doesn't take away from how well it is doing), I can't say most experts will agree with your prediction about the Lion King. Right now, from what I have gathered, it is looking like a top 3 movie for the year.
Just for fun, I did a quick search (please understand this is not real in depth, I just wanted something quick) of the projections and predictions currently for movies in 2019 to see where they have movies landing. Some are way too far out to really get a good read on and will change a lot. Here is what I found some sites are projecting the top domestic box office will be for 2019:
1) Avengers: End Game $850,000,000 (quick estimate on current projection)
2) Star Wars: Rise of Skywalker $666,000,000 [Reddit]; $750,000,000 [IMDb]
3) Lion King $650,000,000 [BoxOfficePro]; $600,000,000 [IMDb]
4) Frozen 2 $500,000,000 [Reddit]; $500,000,000 [IMDb]
5) Toy Story 4 $495,000,000 [BoxOfficePro]; $450,000,000 [IMDb]
6) Captain Marvel $430,00,000 (quick estimate on current projection)
7) Spiderman: Far From Home $405,000,000 [BoxOfficePro]; $400,000,000 [IMDb]
8) Jumanji 3 $400,000,000 [IMDb]
9) It: Chapter 2 $350,000,000 [IMDb]
10) Aladdin $300,000,000 (quick estimate based on other live actions runs)
11) Secret Life of Pets 2 $263,000,000 [BoxOfficePro -- they have actually reduced their final domestic prediction, but I don't recall their new prediction, I only had their highest prediction]
12) Hobbs & Shaw $200,000,000 [IMDb]
NOte - these are not my predictions, or how I feel it will happen. I just did a quick search of a couple of the sites I knew. Point was, it seems pretty much expected across all projections that Lion King will make more that Toy Story 4 (although Toy Story 4 is trending up, so is Lion King at this time) or Frozen 2.
Crazy to think that right now (will change) 7 of the top 10 projected movies for 2019 are Disney, and one other has a connection to Disney (Spiderman)
Quick update - the Friday opening numbers for Secret Life of Pets 2 just came out. They are a bit lower then some predicted, and right now BoxOfficePro is estimating they will make 46 million this weekend. When they were predicting a 263 million total run for Pets, they were also predicting a 80 million opening weekend. How this will play out for its final domestic will be interesting. It should have good legs, but still puts it behind it's "original" track to over 250 million.