Hiya, an early nap can reinforce EW but so can a short A to bed, and I think you're A to bed may be too short
It's tricky getting the balance right.
Personally, I would leave the nap as it is for now and slowly push bedtime later until it's more like 7.30pm and see how his WU does. Since he slept till 7 today it's a good chance to try a later bedtime.
If this doesn't help then there are lots of LO's of this age on the site who are needing their naps capped to lengthen their nights, but try the later bedtime for a few days first.
Hope this helps x