In Kancolle, there is a limit to how many shipgirls you can have. Therefore, if you get multiple ships of the same kind then you'll probably scrap the new ones you get and keep your old ones with higher levels/stats.
He probably got another Ooyodo shipgirl but had to scrap the new one since he can't hold anymore shipgirls. Having to scrap someone that is pretty much identical to your wife must be pretty hard.