That appears correct. NameCheap has very few domains, since most of their domains are really with eNom ...
Hence, most NameCheap customers are really eNom customers - beware that some NameCheap customers have lost domains due to eNom's policies, in particular, their LegitScript partnership - search forums for more details.
As for GoDaddy - looks like their losses were in about the same range as other weeks, but new registrations / transfer-ins were somewhat less... and yet they still showed a gain, nevertheless.
In regards to any boycott working - don't be so sure of that quite yet ... GoDaddy understands the domain market better than most anyone - vast majority of people, especially domainers, shop only on price; more coupons along with some extra promos will, presumably, bulk up the numbers on demand...
However, if GoDaddy, even with promos, starts showing losses and that remains sustained while some other registrars pick up large gains, then that's a whole different story ... time will tell ... imho, GoDaddy, for the foreseeable future, will remain the biggest registrar with much growth.
Ron