There has been no timeline for spawn eggs. A lot of items are currently bugged at the moment so it is just adding to the list. It will most likely be a big announcement when the fixes do come so just keep you eyes open here on the fourms!
I am new and wish I would have known that prior to spending a lot of money on them. I also got a pig spawner. That isn't working either. Ugh. I hope that it works soon because I need it for food. Do they take a long time to fix the bug? I am super excited that it is something that they are working on.
As far as I know, spawners should work. Make sure that your spawner is surrounded by a ring of grass! Passive mobs only spawn on grassy areas. c:
Spawners still work, there's /warp mob and /warp animal, you can also ask a skygod to spawn some mobs in for you.