I don't see anything surprising, as compared to anything we've seen to date.
At 3-3-4-a and 12-2-1-c-Exception 3, the term "available" apparently means that they haven't already used a T/O during this dead-ball period. But, I've always wondered, if we are already in a time out charged to that team, and then some time later (like 20 seconds, for example), their HC wants to make a challenge, is that OK? I would think so. But, the language of editorial 12-2-1-c-Exception 3 to 12-3-5 says, "...if the team has a timeout available..." Well, when would they NOT have one available? That makes me think that, if a team wants to make a challenge, then they must the challenge immediately, (simultaneously) as they request the T/O. If they request, and are granted, a T/O, but wait a little bit, then decide to challenge, then, it seems, by this language, they don't have a T/O "available" at that moment.
So, what does "available" mean?