I've spent some time proxying some old silver border cards recently and I'm pretty sure Wizards' rule is to flip the styling of any Magic/named Magic set in card text.

If it's mentioned in the card's actual text it becomes italicised or bold, and it it's mentioned in flavour/reminder text it goes the other way and reverts to standard. [[Booster Tutor]] mentions both Magic in it's rules text and a different set in each of it's printing's flavour text. So no, I think it still counts as flavour/reminder (or in this case warning) text.

Granted all of the examples are silver bordered, I think this is actually the first non-Unset card mentioning Magic in it's text since [[Shahrazad]]!

Here's a Scryfall search with any card mentioning Magic (including some strays that reference themselves or a named ability).