I mainly agree with what you wrote, but will differ/add a few points:
1) While we would expect/hope for further development at the MLB level, these Japanese signings are for MLB contracts, with the expectation that the signee will be a part of or 2026 rotation, or bullpen as a bare minimum
2) The team cerrainly loses two year's worrth of WAR if the player opts out after first or second year, but the team then loses the risk of injury during the year(s) opted out of. If the player opts out, the signing team is still in a position to sing him to an extension and is the team that has the best understanding of his ability and health. That is advantage. If he enjoyed the city, fellow players, manager, and coaches, then that is a further advantage in resigning him. If he wasn't happy in Philly, it might be best for him to leave.
3.) The Phillies continue to not have signed a significant over-25/posted player from Cuba/Japan/S. Korea. As has been argued earlier, yes, we can sign a FA for those $, but the FAs of comparable talent are older, require more $, and require taking on contractual obligations well into the players age 30+ seasons. There are uber stars and other stars whom opposing teams have acquired from this talent pool. The Phillies put themselves at a competitive disadvantage by not dipping into this rich pool of talent.
- This is the arena in which our larger budget provides maximum advantage. MLB has reduced our Jan 1 bonus budget, MLB system also gives us no competitive balance draft picks and reduced comp when another team signs one of our FA. We are penalized for signing QO FAs. Here, we have the advantage, because the posting fee doesn't count against the MLB salary cap penalties.
The Phillies actions in this arena of talent acquisition seems almost to harken back to the Bill Giles days, when the Phillies always were 'in' on such talent, as a PR exercise, but evidenced to real interest in an actual reasoned signing.
To the comments above listing Hispanic pitchers signed, or traded for by the Phillies as a refutation of racism allegations (and I think the team is far improved in the racism department from the Carpenter and Giles era): we have a budget allocation from MLB for international bonuses -- there isn't a ton of talent not from Latin America which is eligible for the January 1 signing periods.