Is it true you shouldn't talk the same day as you sing a show in order to maintain your voice?

I was watching some videos about how some famous singers e.g. Freddie Mercury, Jon Bon Jovi etc used to rest their voice and deliberately avoid talking to anyone the same day they were doing a show in order to maintain their voice for the show. Is it true that talking weakens a singing voice and makes you perform worse? I've never heard Ken or anyone here discuss this. Is it true or is it a myth?

I've been singing for years and I haven't personally found that talking the same day as a show weakens my singing voice, especially if I do proper a vocal warmup before singing. The only thing that seems to make my voice hoarse is shouting, like say I go to a nightclub and have to shout loud to be heard over the music, the next day my voice will be hoarse as crazy. Actually I don't go to nightclubs these days, but in the past (in my younger days) I did.