Old doesn't mean DCVax L is obsolete but since technology evolves rapidly I'd have to say that yes, its no longer bleeding edge.
My 2010 MacBook Pro is "old" by laptop standards but thanks to the 8 GB of RAM I upgraded it to, and my diligent application of OS X updates old doesn't mean obsolete.
I think they've tweaking DCVax L in similar ways as been discussed extensively over the past day or so. That's rather like adding a bit of RAM and installing the newest version of OS X.
Just like it makes no economic sense to ditch my 2010 MacBook, NWBO has no reason to ditch DCVax L and every reason to take full advantage of everything it still has to offer.