Lots of folks like me can tell you about past July's. No one can really tell you about this July.
For the first few weeks of SWGE (into June) there will be a reservation system to keep crowds more manageable. No one can get into SWGE without a reservation. No FPs either. At first.
After June 23 things may or may not change. No one has said.
A few of other thoughts...
DLR handles crowds differently than WDW. The WDW parks are bigger and handle more people easily. However, DLR has lots more rides per park than WDW. So queues tend to not get as long. For example, until WDW added an extra theater to Soarin and an extra track to TSMM, the wait times there were horrendous. On the other hand, DLR's Soarin and TSMM rides (both of those are at DCA) were 1/3 to 1/2 as long. Not because there were fewer people but there were more things for people to do. They still have 2 theaters/tracks. What I am saying is DLR may feel more crowded in the walk ways but feel less crowded in the queue wait times.
One of the huge advantages DLR has over WDW is hotel proximity. You can stay at a hotel where the door of your room is as close to the DLR gates are as some of the bus and boat drop offs are at WDW. Yes, a 5 minute walk. When you stay that close (and I always do - see "HydroGuy's Hotel Rule"
www.disboards.com/showthread.php?t=1199862) it makes it way easier to take afternoon breaks. And
that helps you manage crowds. You can make rope drop with a 5 minute walk, spend 4-5 solid hours at the parks, head back to your hotel room for some rest from the heat and crowds, then come back a few hours later rested and ready to stay late into the evening. What I am saying is it easier to manage crowds at DLR than WDW if you make a good hotel choice.
Finally, building on the proximity issue I just explained, is MaxPass. It allows you to continue to collect up FastPasses while you are at your hotel resting. See "Comparing DLR's MaxPass to WDW's FastPass+" -
https://www.disboards.com/threads/comparing-dlrs-maxpass-to-wdws-fastpass.3726294/.
Hope that helps!
