So what we are talking about is right-sizing. The right trailer for a given vehicle. Max tow capacities can be deceiving, especially when talking about towing a travel trailer. The reason for that is it's a box. Imagine holding a 4x4 piece of plywood in front of you and running into the wind. Now you get why it's so hard on a tow vehicle.
In theory, if your TV has a max tow capacity of 8500#, it probably could tow a boat or car trailer up to that weight. Both have far lower wind resistance than a box, and both generally have a lower tongue weight due to the design of the trailers.
I personally have towed 2 different trailer/tow vehicle combos close to my rated capacities. It can be done, but it's not nearly as pleasant as leaving some margin. Realistically leaving 20% or more makes for a very nice towing experience.
All that said, why not wait a year until you get the 2500 then get the trailer you really want?
2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE