Huh, I had not heard that. In my experience it's pretty evenly split -- at least, in my circle of friends and family there's eight black cats, four of each. (Most short-haired, one long-haired black cat that's female.)
Let's denote this as Xo and Xb for the genes. An orange female cat is XoXo, a tortoise shell / calico cat is XoXb and a black female cat is XbXb.
Male cats are either XbY or XoY - there are no tortoise shell male cats (there are cats with Klinefelter's syndrome that can be XbXoY but only mentioning this for a full coverage of the topic - and for a real example of this https://disneylandcats.com/cat-profile-francisco/ and it confuses things since XbXbY and XoXoY cats would be difficult to identify without a genetic test).
The thing with all of this is that the genetics for XoXo or XbXb and XoY or XbY are exactly the same percentages.
Doing the Punnett squares for cat coats and all the possible pairings and you get simplified
Genotype Count Percent of XX or XY
XoXo 3 25%
XoXb 6 50%
XbXb 3 25%
XoY 6 50%
XbY 6 50%
Francisco is the example I picked since he's likely the most well known of tortoiseshell (supposedly) male cats.
I suspect that some of the claims that he's female is based on a lack of knowledge of Klinefelter's syndrome.
However, less is said about them and there's less meme / awareness about female black cats being less common.
I suspect this is that an intact male orange cat is much more noticeably male than an intact male black cat.