Lewis is not a road grader type. He is solid in pass blocking but not someone you can count on to run behind, especially in read option plays which requires offensive linemen to hold their blocks longer. He's not very strong at the point of attack. I think that is why Baltimore moved on from him, more than the injuries. They are trying to make a college style read option run dominant offense with Lamar Jackson. They want maulers up front. Lewis is a better fit for a classic NFL passing attack offense.
I think that both of you have good points. I definitely think (or at least hope!) that Douglas will want an upgrade at RG. That said, unless Lewis is that upgrade, I don't think it will happen until next year. I guess it's possible that an older OG who has been very good in his career and who has a large contract could get cut because some team has a rookie or young player that looks great in TC and that team needs the cap space, but it probably not that likely that happens. Cutting Winters this year is the only way that Douglas would save $6.5 million on the cap. Winters will be a FA next year. Unless Winters stays healthy and plays at a high level this season, I definitely think Douglas will look for a new starting RG next year.