As the 2-ways, Brown and Diabate will be the ones spending most of their time in G-league (by requirement). As a non-two-way, if he gets assigned to G-league it will be for the long haul.
As someone who doesn't really follow pro basketball, what exactly is a "2-way"
Here's my understanding. NBA teams have 15 man rosters. Up to 13 of whom can be active for a game. That doesn't mean the last two guys on the bench are the inactives - they could be players taking a night off or nursing an injury. Additionally, each team can have two "2-way players' - these are players primarily assigned to the G-league team. They are primarily on the G-league team's roster but can be called up for a bit over the course of the season (40 -45 days - though that may have changed for Covid). Key is they are G-leaguers first. So it is a good sign Preston is not a 2-way player.
NBA teams can also assign other players to the G-league - and those players can come and go, back and forth, as much as the NBA team wants. Could be vets who are rehabbing or younger players who are simply not getting quality minutes in NBA games.
The key for Preston is to regular get 7-8-9 minutes a game as a backup to Jackson and Wall. If he does then those minutes will jump to 15-16-18 when either of those two get nicked up or take a day off - which the Clippers are famous for.
If he is not regularly getting those handful of minutes, but rather Terrance Mann (combo guard) is getting run at pg, then Preston will only get real garbage time minutes and will probably find himself assigned to and playing primarily in the G-league (in order to get playing minutes). And then only getting called up if there is a long-term injury.
If ranking team's perceived value of a prospect. 2-way guys are third. G-league assigned are 2nd and those getting 7-8-9 / 15-16-18 are first. Guys getting more playing time than that are no longer prospects.
Know he has been recovering from a groin injury, but hopefully Preston will get a few minutes tonight (on national TV) since the vets are still getting their regular season legs. Should know his path by Thanksgiving (G-league starts in early November).