Obviously, I don't know, but my impression is that the Buck family (Tri-Play) sold one-third of their stake to Stan Middleman. Some indication that one of the Buck cousins (second generation now) just had no interest, and wanted the funds for other purposes.
The reported amount of the sale is generally consistent with the reported transfer of 16% of the franchise (implies a similar valuation to that estimated by Forbes), so the sale itself doesn't seem to be injecting any additional cash - it's not selling additional shares or diluting the equity of existing shareholders (except Tri-Play, which is selling shares).
The normal procedure, if at some point the club needs a cash infusion (to fund Clearwater expansion or CBP improvements) would be to have a cash call from the partners. I wouldn't think any of the major partners would have an issue with that (Middleton, Bucks, Middleman), although a Buck cousin who wanted out altogether would probably not be interested in ponying up -- and if such cash calls are anticipated, that may have been a contributing factor in the desire to sell.
We don't know, at least at this point, whether Tri-Play (the Buck family org that actually holds the shares) will be restructured to write out that cousin or not. Rename it as Bi-Play?