Maybe Pena's best use for the org does end up coming as a trade chip, but I certainly wouldn't consider him blocked.
I think Pratt is locked in as the shortstop going forward and I expect Made to be the third baseman soon, perhaps as early as mid-2027. Pena's timeline for arrival in the big leagues seems to dovetail nicely with the likely Turang trade in a few years.
Unless Turang shockingly agrees to a long-term deal, I think Pena is the second baseman of the future.