Online mode is still in the "ToDo bin" as far as I know, apprentice got the letter because they mostlikely started using trademarked items, if have no legal point to stand on with wagic the way it is now they won't have one if you decide to put in a multiplayer or 1vs1 mode or even a tournament held every now and then.
Remember this is Wagic, not Magic, just check any booster pack, we aren't using anything they copyrighted, we don't use their mana symbols, we don't use the artist names and/or art, we don't use Set names, well we do, but we don't, Rize of Eldrazi is ROE for instance, if you decide to use a theme or mod were everything is exactly is like it would be in Magic it has nothing to do with us, that is fan made stuff and they won't even bother to sue the fan.
As for apprentice, I can't really recall that well but I think they used the official mana symbols.
But anyways that's my point of view it's up to Wololo if it will be included in the official releases buuuuttt you can always make a fanmade patch with the help of some programmers that care for this project and want to write the Online mode or whatever.
Just a suggestion if it won't fly in the official releases