Personally, I would insist they not touch them. No need to replace or put new sealing washers on in my opinion. They are only 3, at most 4 years old. I have the originals on a Toyota manufactured in 2009 with 580k miles. I know the batteries are on borrowed time but they continue to function just fine. I do my own tire changes so it's no big deal when the batteries finally give up and I need to replace them.
It wouldn't hurt to gently snug them up with the appropriate deep, six point socket. That's something I would much rather do myself. I know I won't over tighten or mar them. YMMV