Dragon Commander is set 8800 years before Original Sin (see the Kickstarter
update #13), so none of the regular characters will make an appearance (there's always a chance if there is a sequel to DC, though). Maxos lived quit a while before leaving on a quest (and not returning to Rivellon by the time of Divinity 2, 1300 years after Original Sin), but I don't recall how long it had been since he left. It was long enough Maxos was known to few historians in Divinity 2; his battle tower on Sentinel Island remained empty for quite awhile before Laiken was able to get through the protection spells, and Laiken was there long enough the island itself was corrupted.
The main character from Dragon Commander theoretically could live that long, being half dragon.