If you stop to look at the number, the 555 area code is used for Movies, and 8675309 isn’t used for obvious reasons. (If you don’t know, that’s just sad.)
I know I’m not breaching any ToS, I just don’t want any ToS strikes due to some bot thinking I’m giving away someone’s personal info due to formatting.
I don’t think there’s any way that anybody could actually know that, but what if you delete the second dash and replace the first dash with a period or underscore? Even though calling the number wouldn’t connect you to anyone, it’s probably best to be cautious.
I’d say that you should be good as long as it isn’t a real phone number, although if you’d like to be on the extremely safe side I’d recommend uploading that number as a decal on an alternative account.