2: The Spurs can offer Devin Vassell a five-year contract extension
One change directly impacts the Spurs. They can now offer Devin Vassell a five-year rookie extension without having to sign him to a max contract. That's a big deal since the Spurs can lock Vassell up for six seasons, including the final year of his rookie deal. Had this rule been around last season, the Spurs could have done the same with Keldon Johnson, ensuring that two young, talented wings are on affordable long-term contracts.
Considering Johnson signed for less than $20M a year, Vassell could and should ask for more, and the Spurs will likely oblige so long as they get him under contract for an extra season. That would be especially important since the salary cap will skyrocket after next season. Even if San Antonio agrees to a five-year deal for, say, $110M with Vassell, that could lead to significant long-term savings for the team.
That doesn't account for the strong possibility he will continue to improve. Assuming Vassell does, it could be among the best contracts in the NBA in just a few seasons.