That new waiver rule was just a suggestion as far as I know. Especially considering the lack of support that it saw. But yes, as the rule is suggested, an 18 year old IFA signed to a MLB deal would be eligible to be claimed on waivers if the 18 year old wasn't on your starting roster
NYY GM (2010-2017):
791-507 (.610)
4-time ALCS Champs
2014 World Series Champs
791-507 (.610)
4-time ALCS Champs
2014 World Series Champs