MSL has fairly consistently taken a cautious approach with the young guys and taken it slow. With Huston that meant being on the 2nd/3rd pairing alongside Savard and 2nd PP unit. Once he showed he could handle things he would be given more responsibility, once he could handle that more responsibility, and that process is or at least would've continued if not for the Guhle injury. I would expect something similar with Demidov, 2nd possibly even 3rd line if we go big name hunting during the offseason moves, and PP2 to start and then quickly given more and more responsibility as Demidov shows he can handle it.
I would imagine the ultimate goal is to spread the offence among multiple lines, so chemistry will probably determine whether he ultimately ends up the 1st or 2nd line. But the line numbers are likely to be a meaningless distinction in the same way that Evans technically being the 4th line center is meaningless given his usage is that of 3rd line center. Demidov end up being used as a 1st liner even if he's on the 2nd line, you can think of P. Kane in Chicago's hey days, he was often playing on the 2nd line and Toews was on line 1 because they wanted to spread the offence around.
