TM'ed Psychic on Alakazam for Future Sight - Mistake?

It occurred to me that after I used a Charged TM on my 97 IV Alakazam with Psychic I may have made a mistake. What if, one day, they change movesets and Psychic becomes a two bar move, still with 100 damage, a bit like Outrage? It's legacy and he was my only Alakazam with Psychic.

I don't know if this is a legitimate concern, but in light of cases like this people may be more inclined to keep current less-than-optimal movesets in case they become better, especially if they are legacy. Should we worry about this? I could have used it on a Shadow Ball Alakazam as I have a spare, but it's got worse IVs and would require the 75k dust to level 30.

Edit: Thanks for the perspectives and contributions everyone. I was soloing a Machamp raid and it made the difference between success and failure, as I had only one other FS mon (Espeon), so it was a bit of an impulse decision.