You may want to check out this thread on reddit where a user, your friendly asi, supposedly a safety inspector, is talking about it. Here is what he has to say to a doe about what the asi doesn’t think a dpe will be able to continue giving checkrides during the shutdown.
“Exactly, you are a representative of the FAA, and you conduct work on behalf of the FAA. Without the FAA operating like normal, your designated work is suspended until we are open again.
Your POI will probably get ahold of you on Wednesday since Monday and Tuesday are holidays, and give you the run down if they haven’t resolved the budget by then."
There is another post by someone who checked with their testing center and confirmed they are not allowed to administer written tests.
I agree that following logic would suggest this shouldn't affect checkrides, but I urge you to separate what seems logical to you from the "logic" of the gubimint.
I certainly hope this isn't the case, as I passed my IR checkride Tuesday, so I hope my plastic isn't held up. I also wanted to take my CAX test next week. So I hope this all to be internet lore.