I think it will be an eight-team regional this year.
Gonna go out onto the limb here...
Let's look at the concentration of teams which the NCAA needs to send to regionals by bus and not fly, I think that the NCAA puts the 6-team regionals at:
West -- McMinnville -- with room for two (non-West Region) teams from the Central Time Zone to be flown to Oregon, especially if the West only has one Pool C bid.
Central -- Memphis -- BSC moves into this region and Pool B Wash U. plus SLIAC, CCIW and IIAC and a Pool C.
South -- CNU -- Southernmost of the regionals in the Eastern time zone (CAC, ODAC, USASouth).
Midwest -- Prucha -- I have trouble finding 8, especially with 2 apparent vacancies in the West, even moving the Midwest Conference into Prucha.