>>281581708
No, anon's just naming them that because we don't know Yamama's maiden name.
That said, I think it is a thing in Japan for the man to take the woman's name when the woman's family is higher-status or he's otherwise marrying into her family more than she's marrying into his, so it's entirely possible that Yamadad's original last name was something else and Yamama was a Yamada all along. But this chapter doesn't make it clear either way.