My idea(s) are for the use of flying cameras. The first one being that once you are dead in a solo match, or once your whole team is dead in a duos or squad match you would then have the option to use a flying camera to move around the map and watch the rest of the match. This would be in the same vein as what happens upon death in ARMA 3's Battle Royale. Though I can understand to a degree if this isn't wanted with the fact that there are those out there who team up beyond the group limits of the match types, and this could mean people could cheat further by telling their extended team-mates where people are.
The second idea regarding flying / free cams is an offline mode, basically where you can explore the map on your own with the ability to change to thing flying camera to look around. My reasoning for this (which also extends into the next suggestion I'm going to make) is it would give people a lot more scope of what they could do in terms of making videos and thumbnails for YouTube.
My last idea sort of goes hand-in-hand with my previous one. Essentially an offline mode, which for all intents and purposes could be the same way you get to explore the map with a flying camera, but my thought is that it's a way you could play in the map(s) with only your friends. Not set up as a match or anything, just wandering around and exploring. Not only do I think it could be generally interesting to be able to do but, once again, I think this would open up a lot of things for people to be creative with making videos for YouTube - if nothing else it would be easier to make machinimas. I believe this is somewhat possible to those who have access to their own servers in the game, but (unless I'm mistaken) as far as I'm aware the availability to have those is pretty limited, and this would be a way people could do more with the game without having a personal server for setting up matches (as they wouldn't have to run matches at all). If I'm wrong about the accessibility of getting a personal server then I'd be more than happy to be proven wrong.
Anyway, those are some of my ideas. Apologies if they're ones that have been made before and I've missed them. Would love to know what people think.