But, here's the BIG thing...the whole point of this post....If WotC abandons 4e, I'll never buy any 5e stuff from them.
If I know that I can come to rely upon a digital subscription, and it is one that disappears, then I'll not ever buy in to that subscription. I don't have a personal investment in 4e, but I'll be watching very closely with what they do with it, and how they treat its fans. If they want me back for 5e, they damn well better not squash 4e (or I know what's coming next after 5e turns to 6e and expect them to squash 5e).
So, from a person who really isn't that big a fan of 4e, WotC, please continue to support it digitally (whether that's a bundle single purchase of all products instead of continuing montly support, I don't care).
I just don't want to, when 5e is released, hear how WotC tried to destroy 4e so everyone would play 5e....because that is EXACTLY what would prevent me from playing 5e (and, again, I don't even really care about 4e).