Can you wear buzzed hair (particularly on top) with FUE if you continue to lose hair?

[22able]

I know that HT's are permanent. However, if I had a procedure to fill out the thinning across the top..could I buzz this down if my hair started to go south over time? I am looking at an HT from worst case scenario where I lose more hair. At 25 I would be overjoyed to be able to have my hair for another 10 years so that I can make up for lost time. If, after that, I can no longer style it..I want to know if the option of the buzzing the top completely (to zero) exists. Can leave the sides and back a little longer to cover donor marks.

Background:
25, Diffuse pattern thinner (thin all over the top), been on propecia almost 2 hairs, hair loss is stable - losing since 17. Considering an FUE procedure soon. Very noticeable loss but 2000-2500 grafts would make a significant difference because of the way I style my hair.