I sure hope he sticks around. He would be the anchor on a rebuilding line. With a couple of seniors gone for sure, and Edwards a junior who might leave early, we already have 2-3 open spots on the line for 2019. Four spots would be tough to overcome.
Van Lanen will likely be the starter at LT next year. Dietzen, who is battling back from injury would be a solid candidate to play LG (or RT). If Biadasz is back he's the starter at C. If not, Erdmann would likely be next up or maybe Lyles who would have to make the transition back from DL. The problem there is that with Sagapolu gone next year they will be really thin at NT next year so they may still need Lyles there.
On the right side, Moorman might be the next best guy at RG and if Edwards jumps, Bruss would likely be the RT. It'd be a young rebuilding group. They have some really good young guys waiting and more coming in 2019 so the line should be a strength going forward, but 2019 might be a step back if 4 starters all make the move to the NFL.