I would love to learn Arabic. Are there any estimated release date?
There is no such date.
Would you please care to use the Search option before posting? If you did, you'd see a lot of questions about new languages including Arabic. However, the team rarely gives any answers about new languages. At least, I've never seen any comments from the developers about Arabic.
Duolingo really needs to make discussion and Q&A easier to navigate. I've spent a lot of time trying to search for answers that I haven't found. But yeah, new languages discussions should be relatively easy to find.