I have mained jungle for a long time (miss my old WW) and I started playing other roles because jungle just isn't fun right now. Jungle is already the most complex and difficult role and now it is just a free for all for whoever wants to invade. It is so easy now for a team to put a jungler behind and make them useless (minus the few duelers who thrive in this). On top of that you get flamed NO MATTER WHAT YOU DO! You can be pulling every objective, a positive KDA, and the second a laner loses 1 v 1 to their opponent it is somehow your fault. There is a lot of weight on you and it is really easy to F up.
So it is not surprising that it is going to end up the new autofill role. Right now jungling is just not fun. The problem is that it is probably the last role that should be autofilled. It is far too easy to abuse someone who does not know what they are doing and a good jungler then gets free reign on two jungles and can gank all day without risk.
The problem is that you cannot have jungle just be removed from autofill. The only way to fix it, is to make jungle less of a chore and more fun again so that junglers go back to the jungle. Personally I do not see a point in going back in when there are so few real viable options. Until season 8 you could play almost any champ in jungle and at least hold your own. THe meta right now is far too restrictive.