My boys are both low sleep needs, DS1 never had, DS2 has had only a handful of 12 hr nights so far. Now that it's warmer and we're outside more, and days are longer our days are lengthening as well. So, DS2, who is 21MO is usually up 630ish, has a nap of 1.5 hrs and BT is 8 pmish.
If your LOs sleep needs are also low, I would try pushing BT to 6.45ish for a few days and see if he continues the EW. That way you don't push him too much, but you'll be able to see if anything changes.