One of the main reasons for this change is roster size. Too many teams felt they had to have a long-distance bomber kicker AND an accurate field goal kicker...add in a punter and you have three roster spots going to kickers. This rule change will allow the regular FG kickers to kick off again and eliminate the need to a “kickoff only” guy.
That being the case - returns shouldn’t be effected that much. The coachesd were behind this change (note: the run-up to the ball is also being decreased from 15 to 5 yards).