Most probably.
This is how basecamp always did thing, even back when it was called 37signals: they release a MVP, they generate money as early as they can, then they start agile feedback loop, improving the product throught many iterations.
They were one of the teams that made agile popular after all.
They also promote the philosophy of rejecting features and not noting the requests for them down.
Only a feature that has been requested and rejected enough times pass their "filter" of something that should be added to the product.
I'm betting a custom domain name will pass such filter and end up being implemented in one year or two.
