All that the CBA says is that "Exhibition games prior to any Regular Season shall not exceed six" and "Exhibition games during any Regular Season shall not exceed three (3)" and "Each Team agrees that in no event will it play more than eighty-two (82) Regular Season games."

So the league can, consistent with the CBA, decrease the number of pre-season or regular-season games, they just can't increase it.

The only real CBA issue seems to be the following: " the number of days beginning on the date of the first Regular Season game and continuing through the date of the last Regular Season game each Season shall equal approximately (177)"

But there seems to be a lot of room in that approximately. For example, this season it was 169 days between opening day of the regular season and the last day of the regular season. If it can be 8 days shorter than 169, it should be able to be 8 days longer than 177, i.e. 185 days, especially if they are reducing the pre-season games. Those 16 extra days would probably help a good amount in reducing back-to-backs.