Disagree. Under the last system, seniority was irrelevant. They assigned training dates in seniority order with no regard to what senior people wanted to do. You're first on the list to train and the training date starts June 1st, over your summer vacation? Tough. You send out dozens of emails and work it out yourself. At least now, if you're the senior guy, you can just bypass until after the summer and take the next spot that works.
Are there issues with the new system? Sure. But this solution is a bit of an improvement. It traded a big problem for a smaller one.