I can't argue that it doesn't
sound really good...BUT, reality is that water lines get a coating that builds up on the inside after some time...at that point the water doesn't typically actually touch the pipe, unless the coating is disturbed in some way...heck, at one time it was very common to have lead water pipes bringing water to your house...I'm sure there are still some out there in some towns...so forgive me if I don't feel "rescued" by the EPA for getting rid of the small % of lead in brass fittings.
And even if you still have lead water pipes, its about contact time...so as long as you run the water to purge what has been sitting in the pipes for some time, it can't really pick up lead on a quick pass through a lead line, let alone just a leaded brass fitting or two.
I'm sure
@Highbeam has some additional input on this one too...not that it has anything to do with the OP's topic.