The Rams (pretty much all teams) have a plan for multiple scenarios.

I have no doubt that Rams have a plan for Center or they wouldn't have let Blythe go for what is NFL chump change.
What's the plan? I have no idea.

But Blythe was pretty aware he wasn't going to be a Ram this year. This tells me he knew a plan was afoot..... but he (of course) didn't know what it was. Only that he probably wasn't going to be part of it despite all the glowing things McVay said (when will we ever learn to stop hanging on coachspeak).