1) How much better of a trade chip is a 25yo player with 5.5 years of cotnrol vs a 25yo player with 6 years of control? I don't think the extra half-year of control adds much to the equation.
2) It's really tough to argue that demoting Taylor or Valdez to keep Houck on the roster constitutes going "all in". By this logic, the Sox should demote Devers to Worcester for the season and get the extra year of control. In fact, that actually makes more sense that trying to do so with Houck. (Which still doesn't mean it makes a lot of sense.)
3) Actually Tampa's approach has been to lock up younger players as early as possible, with prime examples being Evan Longoria and Matt Moore, neither of whom had a dozen games under their belt before signing extensions. The goal is to avoid the rather unpredictable arbitration years. More recently, they have been trying to get something done with Randy Arozarena. And we can all expect Brandon Lowe to get such a deal at some point this year or early in the coming off-season. Now, they will probably deal Willy Adames this offseason, even amidst the overcrowded free agent shortstop market, but that also involves a potential clearing for top prospect Wander Franco, and not an attempt to avoid paying him...