Why?
Will it add Top Fighters to the Roster and we'll get more fights of a higher quality?
Or just be the same fighters ranked in two or more different weight classes fighting the same amount of times, but stretched over numerous Divisions trying to pursue trophies based on "ideal" weight fookery and opponent advantages??
Maybe, the UFC should just get ALL the current fighters in the Top 15 of every Division fighting every 6 months to create a proper churn of rise and fall. UFC hasn't maxed out the competitive landscape in the current Divisions, in large part due to Fight Inactivity and Selectivity especially in the Top 10, as they look for Money-Fight Matchmaking.
More weight classes means more cross over champions, "super" fights, rank squatting opportunities, etc. the kind of crap that slows the flow and makes a mockery of this sport-entertainment -- so we accept that it's a game both behind the scenes and in the cage.
It won't add more quality fighters, just spread them out across more Divisions. UFC needs to maximize the current roster in activity and opportunity to rise to the top on merit without delay.