What I think really happened :
Zayn got kicked out of the group due to high activities that were trespassing the label rules about affiliation with other musical groups/producers, etc. Given the fact that the statement on the website said Zayn wanted to live a normal life and nothing of that has been done ever since they announced his departure, its clear those weren’t his words. Now let’s talk about the fact Zayn has just not spoken to ANYBODY ever since March 25th (my birthday BTW, so I’m devastated), his twitter hasn’t even been updated since March 18, when he tweeted about his love for Perrie Edwards. (Also, Zayn still has the 1D next to his name, im crying.) So, the “stress-leave” was not because of cheating rumours or what not but because the band label was giving him some time to think and idk re-evaluate his relations. (You can tell idk how businesses work-I’m also assuming.) Zayn, being a high celebrity, needs to make some kind of money after being kicked of such a grandiose job, so he turns to Naughtyboy who he has been communicating with frequently. This may also explain why Louis (and prob the rest of the band) have hate/are in feud with Shahid Khan because he is the reason why Zayn is in a pickle. Hopefully, my biggest theory will happen : they are all trying their hardest not to spoil the prank they’ve been working on and are waiting for April’s fool to say it was all a joke, Zayn isn’t out of our lovely band and “I won’t mind” is a promotional part of their next single that features a new genre of sexual r&b. I’m very hopeful.