I think this is true, and I think also (trying to phrase carefully) there is also a sexualised element to pushing lesbians' sexual boundaries.
I'm in my mid thirties now. I strongly remember in my late teens using the (truthful) excuse of my lesbianism to politely decline the advances of random men in the street and sometimes casual acquaintances, friends of friends etc. It seemed a more tactful way of rejecting men when I couldn't be confident in how they'd react to a more personal (or more 'just fuck off') rejection.
The number of men who excitedly told me they'd slept with lesbians before... Same vibes with many of these lot.