Seems to me that could work the other way as well.
The Committee could say less than 1237 delegates is required for the first ballot nomination, an dpick a new number.
A lot can happen between now and July. In fact, the next meeting of the Rules Committee is in April.
If Trump doesn’t get 1237 then he either overestimated his strength or was too proud to make a deal before the convention to get the 1237... either way tough luck for Trump.