You're going to run into definitional problems in trying to tie this up I imagine. "Feminist" is a label shared by disparate movements, some of whose core beliefs are contradictory (notably the AP and SP feminists have very different ideas about the role of sex and erotica in our society). As a result you will see a big difference between the rate at which people surveyed self-identify as "feminist" compared to the alignment of their beliefs with various beliefs characterised as "feminist". You get the same problem to a different degree if you ask whether survey participants are atheists, whether they're gay or straight, or indeed even if they are human.
I don't see any indication from this statement, at least, that Debian has a problem with people who choose not to identify as feminist or even those who, (more strongly) choose explicitly to identify as not being feminist.
On the other hand, for a very inclusive definition of feminism as just the belief that men and women deserve equal rights it's easy to imagine potential conflicts for someone who rejects that claim trying to work within Debian. Such a person might feel, for example, that women shouldn't be permitted to vote, or that their votes should count for less when Debian selects a new leader. It's pretty clear that Debian isn't about to change policy on that, and if they can't live with it then probably Debian isn't for them.