The value of sharp intel,as you described, is not nearly high enough for a track to keep the sharp on their books. There aren't any legal books left who allow unrestricted sharp sports action.
Any horseplayer who wants a change over to fixed odds has to realize it's a short term play and understand that they will be out of action long term.
In every jurisdiction on earth, books have limited, then banned sharp horse action. So much so that there are Minimum Bet Laws in place in places like Australia where the government has stepped in and forced the books to accept specified minimum bets from the sharps. However, eventually books are able to terminate the sharps there over time.