If I recall correctly, DC was going to great lengths at this point in their history to reaffirm that their older heroes were still 'hip'. There's another story with the Blackhawks which basically consists of some of the older heroes telling them over and over again that they're old and washed up and irrelevant, and should retire. Naturally, the 'Hawks don't take that lying down, and they... start wearing ridiculous costumes to prove they're still relevant. Yeah, that didn't work very well.
As a big Metal Men fan, it's gratifying to note that they're not portrayed as jerks here. There's none of the 'go home, you wheezing old fart!' attitude that was found in the Blackhawk story - instead, they're genuinely regretful that they're replacing a comrade in arms, wish him well, and Tina gives him a hug on the way out. They're happy to have the job, but sorry that it involves booting out an old friend. It's a nice bit of characterization - they're his replacements, but not his antagonists.