Track 3 going OOS on the Hudson Line?

Track 4 came back into service on the Hudson Line north of Tarrytown last week.

Notices have now gone up at Scarborough stating that all counterpeak services (both morning and evening) will be replaced by buses at Scarborough and Philipse Manor starting August 1.

The only reasonable explanation for this that I can come up with is that they're taking Track 3 out of service between Tarrytown and Croton and running all stopping trains on Track 4. (Because Track 1 is unelectrified, they can't just use bridgeplates on Track 3.) And there are just too many trains in the peak direction to even think about running trains on Track 4 in the opposite direction.

Anyone know with certainty what's happening?

Pondering possibilities.... Hence the timetable change at the end of the month. Interesting.

For the record I do not no know with certainty.

The work they were doing on track 4, they will now do next to track 3.