They offered Semien a long term deal before settling on one year, so maybe they'd be open to overpaying him after the season, but my guess is the long term offer they gave him prior to the season was slanted towards the team, and his next FA deal will not be. The front office has spent big in free agency, but in the two recent examples, they went with Ryu (pitching) and Springer (an outfielder in an org absolutely devoid of capable OF talent). If the team views Martin and Groshans as long term pieces, then I could see them continuing to go short term with infield/outfield fixes until they can incorporate those guys in.
Of course, I'm not saying the Jays can't re-sign Semien and still incorporate prospects. They could. Also, prospects fail while Semien is a legit elite talent, so obviously bringing him back is the higher percentage move short term. Just that would they spend over $100m to do it?