Jolly 4 will take Jollibee's place in the lore, it will give us an immediate sequel to what happened after the investigator found the Springtrap suit at the end of Jolly 3 chapter 2, from what we could see in the trailer all the place began to collapse for some reason, and I don't think it was due to time and wear and tear on the place, since we would have had some signs of the little stability that the underground facilities had before going for the suit, and no, the failures with ventilation and cameras were due to the age of the equipment, not the general structural instability of the place. The little we could see after that was that the investigator returned by the same elevator he came down from, since not knowing the area well and not having time to look for another way out, this would have been the best, while we're going up we received a call from Theo, the investigator's partner, who served as a tutorial in both chapters of Jolly 3, probably to warn us or give us an escape route from there, which would not give us any danger other than the collapse, remember that all this happens after 6am and the training animatronics being Jolly and George, and the security animatronics being Maxie and Tweetie should be disabled, or at least that's what we know by having free rein to do the extra activities of each chapter after 6am.

The next part of my theory is about Kevin Johnson and his soul capture project, which we saw in Jollibee's and Jollibee's Phase 2.

We must remember that Kevin Johnson is still the CEO of Jolly entertainment, since we remember that he was introduced in Jolly 3 and not in Jollibee's, for which Kevin continues to occupy his position, and due to the development that this character had in Jollibee's we could get to see his soul capture project that was talked about in the Jollibee's Phase 2 memo back in Jolly 4, this would give meaning to the phrase "Finish what he started", we would finish what Kevin started.

If the investigator comes out alive from the Jolly entertainment underground facilities, we could already know the identity of the protagonist of Jolly 4, who would be the same investigator, since we remember that having completed the 5 nights of "security guard training" we were given a keycard, which gave us full access to the facilities, basically we had registered as a security guard of Jolly entertainment, do you see where I'm going? the protagonist of Jolly 4 will be the same investigator, the gif that IvanG gave us about the ventilation systems of the Jolly 4 warehouse strengthens my theory, that panel shows us the ventilation and temperature control systems, things that we already saw in the chapter 2 of Jolly 3, we could say that the investigator already knows how to handle those systems, and I predict that Jolly 4 will not have a very long tutorial, since the investigator is already a registered security guard, is this one of the reasons why that IvanG told us to play the previous games? It's very likely, then, that the investigator would be here to take down Kevin Johnson's soul capture project by posing as a security guard, just like the protagonist of Jolly 2 did.