The Speaker is dealing with a very slim majority so the decision to postpone votes until next week might relate to the prospect of his majority being increased by at least two following the special elections in Florida. While the issue involved in the rule change might not seem significant, allowing a small number of members to successfully defy the leadership by aligning with the opposition party is very detrimental to maintaining party discipline. This has always been the difference between republican and democrat leadership success. Democrats impose discipline while Republicans herd cats.