It could be any of those. Since I saw getting another 4 as a real need, and not seeing any interest such as Morgan following a player (only two guards this year that went elsewhere) I conclude that Geno feels he can cover the backup 4 issue without one on the current roster.
That suggests a couple of possibilities. He thinks Morgan will be healthy and productive at a Uconn level and can cover the 4 position some. That still would be favoring small ball somewhat, a trait he clearly went to last year. Morgan can play there, but while she is a very good rebounder for a guard, and probably average for a 3, at the 4 it would be somewhat of a disadvantage.
My other thought is because of Olivia's perimeter skills on offense, he might want to play her some at the 4, with Jana or Gandy at the 5. I think on the offensive side the Big O could be fine at the 4. The question there would be the 5. This last season Geno did not have enough confidence in his 5's to use them for 40 minutes a game, going small for part of the time. If Jana made a pretty significant jump and Gandy was suddenly rotation worthy, then sure Olivia and Morgan between them could have backup 4 covered. But there are a lot of hopes, iffs and buts in that scenario, so I am surprised that it looks like he didn't feel to need to address this.
A third consideration may be for beyond this year. Long and/or Hassel look to be key recruits, and I think we need one of them very badly. A one year portal rental wouldn't affect the recruiting of them but a player for more than one year could have. Maybe that was a factor, I don't know.