The easy answer to your question is yes.
If you continue to add/insert files into the Community Folder load times will increase. This perpetuates with each file you add.
I recommend a MASTER COPY of the Community Folder somewhere else on the computer from which you can pull only the files relevant to your current flight, such as airports, planes, etc. This will minimize loading times due to Community Folder content congestion.
As Asobo updates Microsoft Flight Simulator, the downloaded files in the Community Folder MAY have to be updated, as well, to continue to work and not stall loading into the sim.