Theory: We already know the Theme of the next Collection Event.

When season 2 began we all were able to unlock banner frames in the Battle pass which were very Medieval based, at the time these banner frames really didn't make much sense or was on theme with really anything we seen. Then we had Caustic in his Prince/King skin and the Jade Tiger Octane skin as unlockable. Little later the Collection Event was revealed to be a Medieval theme. The Caustic skin matched this as well as the Octane skin in the Battle Pass and it turned out those banner frames matched with the skins that you could buy in that event.

Why is this relevant? Well Season 4 seems to be setting up the same thing. We're unlocking these very Cybernetic banner frames for characters, all the character skins unlocked in the Battle Pass are Cybernetic themed with characters either being cyborgs, or robots. I believe that each banner frame we have of characters that didn't have a skin in the Battle pass is going to get a Skin in this new event to match, which will be a Cybernetic/Cyberpunk theme. And I think this event will more than likely happen at either the end of the month going into March, or the Begining of March.

Does my theory sound plausible? I think.