Correct. It's only a short term cut back of 65/66/67.
It's part of the 5-year Hell Gate infrastructure project. The 1st phase will take one track (or one section of track) out of service between NYP and New Rochelle from March to Sept this year. I think a good guess is they will do the same thing for the other track next year. If they need to turn off the power in both directions to do some of the electrical work, it would make sense to suspend the only trains on the track that run in the middle of the night (i.e. 65/66/67) so they can work an uninterrupted overnight shift. A lot of the work may NOT require turning off the power, so if they are managing things well, 65/66/67 may resume much sooner than September. Who knows? Neither Amtrak nor Metro-North are noted for transparency.
BTW, 66/66/67 were suspended due to Covid and when they resumed, they lost their sleepers. I've taken the 66 (NYP->BOS) a handful of times before they added the sleeper (a year or two before the pandemic suspension), and it is very hard to sleep (or even rest) in the normal NEC day coaches, which lack window shades and leg rests. I was really looking forward to a roomette next time!
Trying to catch a few ZZZ's in the old NYP Amtrak waiting area was also really hard. The last time, only half the waiting area was open at about 11PM when I arrived and about 1AM, they woke everyone up and forced us all to move to the other half of the waiting area. I understand the new Moynihan hall is closed overnight and you still have to wait in the old, dreadful Amtrak NYP waiting area for the Night Owl.