To be fair those characters have been requested for a long time. Also I think it makes more sense for DLC characters to be from a series that has or had represesntation in Smash already. It would generate a lot of hype for Smash 5 if a totally new IP was introduced.
Ryu's a lock.
Isaac's a near-guarrentee.
Let's say we get 8 characters as DLC
4 Veterans:
, all from pre-existing series.
4 Newcomers: Ryu (Third Party, new series, only pre-ballot Newcomer), King K. Rool, Isaac, and Inklings.
5/8 would be from old series and 3/8 would be from new series.
Would that really be that bad?
If Dixie and Bandana Dee get in as well, that's 7/10 old, 3/10 new.
If we view the DLC as a full expansion pack for Smash, this seems more than fair and accurate to what we have already as additions to the roster.