It’s like saying “Your Tinder profile will NOT contain any data/details about you or your dating search that will undermine you in your current relationship.”
Another way to look at it: either you're a replaceable cog, or you're essential to running the business. If you're essential, they're going to do whatever they can to keep you. If you're replaceable, they probably don't care that much whether you in particular stay or go, but it will certainly cost money to replace you, which they'd rather avoid spending.
Only a completely irrational company would cut someone loose just because an online profile with that person's name on it appeared somewhere.
The Tinder analogy is imperfect because of that, but it's still a good illustration of how just the existence of a profile can destroy your plausible deniability.
It definitely is.