Here's what I have so far. Quite the mess in AAA!
2019 MiLB Affiliation Changes
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Class AAA
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New York Mets purchased the Syracuse franchise, leaving the Nationals without a AAA affiliate as of this writing.
The Las Vegas 51s are moving to Syracuse to fill the hole. Syracuse Mets, perhaps? Las Vegas has a new stadium ready for 2019, retiring the aging Cashman Field for minor league baseball.
The Colorado Springs Sky Sox relocate to San Antonio and acquire the Missions name, effectively elevating the Missions to AAA status.
Class AA
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The San Antonio Missions relocate to Amarillo.
Class Advanced A
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The Buies Creek Astros relocate to Fayetteville, NC
Class Advanced Rookie
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Helena Brewers relocate to Colorado Springs.