I also wonder what the other Stones will do. I think they have a few options
1. Split Up Entirely. With the former Stones either joining new bands or becoming session musicians.
2. Form a new band with a new singer and a new guitarist to take the place of the imprisoned members.
3. Wait for Jagger to serve his sentence, but hire a new guitarist to replace the still imprisoned Keith Richards.
4. Wait for both Richards and Jagger to serve their setences and go on hiatus for a year.
I think it will be a mix of the first and the third option. But then again, I could be wrong. By this point, Brian Jones, if I remember correctly, already was not on good terms with Jagger or Richards, and in 1967 he was not as far gone as he would be a year later. In 1968 you have claims that Jones had forgotten how to play a guitar, but in 1967 he's still as talented an instrumentalist as ever, and he could well take the imprisonment of his bandmates as an excuse to leave the group. I don't know as much as I should about Jones, but from the little I do know I think, in 1967, he could have found success as a session man. Then again he was closer with the remaining Stones than he was with either Jagger and Richards, so I could see him being a part of a rump band if it was formed.