The league needs and should balance the divisions out, I think 12 is the magic number as it means a top 5 finals series
I think with some leagues being top heavy, look at D2 Men its good to have 12 teams means bottom half plays meaningful games against each other, likewise D1
Can't see why you wouldn't add Altona and RMIT both showed to be leading in that division, Wallan looked the goods but its the same question as Keys are they good without Black? is he returning etc etc
Send Corio up and Bellarine if they are keen why not
The league wasn't going to promote winners or relegate losers, this isn't about winning Casey/Keilor moving creates gaps in the league and COVID has shown some clubs have taken a hit for the sake of an even competitive comp its always worth evaluating.
Said it before - you apply every year. I worked for a club that applied every year for its womens team to go up a division to match its men, they got knocked back for a few years before it was allowed.