Among schools that will feel impacted by the impending demise of the SMR8, the front of the line is heavily populated by 1A schools.
For it has been in 1A that the argument has been most vigorously advanced that the SMR8 provides a relay opportunity for schools that can't cobble together four 100 meter legs or, more typically, four 400 meter legs, but who can put together four girls to run a mixed relay.
Doing away with the SMR8 does away with that mix-and-match opportunity.
Nevertheless, doing away with the SMR8 does have the virtue of helping to bring a more level playing field to the 1A ranks.
It's been observed since 1A track and field got its own separate classification here in Colorado, that top teams were able to quality most or all relays for state using largely the same set of girls, thus (almost) guaranteeing themselves state meet points in most or all relays even though often two or three of those relays would have to be significantly offloaded at the state meet. You can peruse 1A state meet results from years gone by and find several examples of exactly this happening. You'll find more evidence of that if you have access to the seed times for said relays and can compare State times with seed times.
Removing the SMR8, then, moves 1A track and field a step closer to integrity in state meet scoring. It reduces the count of relays, meaning the remaining relays are more likely to be composed mostly or entirely of the girls who qualified the relays.
Will it remove entirely the temptation to qualify and offload? No, but it is a solid step in that direction.
Before we walk away thinking this applies only to 1A, it should be noted that plenty of 2A through 5A teams have, over the years, qualified an SMR8 for state on the strength of one very good 400 meter type and then removed her from the state meet relay. When in happens in a classification other than 1A, the probability of scoring in that relay rapidly approaches zero, but it does happen in these classifications even so.
Relay qualification is always open to that kind of exploitation unless someone wants to monitor the legs of qualifying relays all season long. Reducing the count of girls relays from five to four, however, diminishes the window of opportunity there. The net result, then, is a better match between athletes used to qualify for State and athletes who actually run at State.