Unfortunately, I have no long term experience servicing forks. I know some riders do rebuild theirs. Your chain, spokes, brakes, and cassette will need much more regular maintenance than the suspension.
Could you take away a curiosity of mine? I went to the Trek website and noticed that they have already released the 2021 E-bikes but no E-bikes have the 4th generation Bosch engine, not even the E-bikes that cost 12 thousand euros.
I'm not an expert but is it possible or am I reading wrong?
I attach the link: