Short answer, no. Esri does not hold themselves to any specific schedule or timeframe for releasing products or patches, with the one exception being ArcGIS Online having quarterly updates. That said, their releases aren't completely random, and there have been some fuzzy timelines that seem to hold up between version updates. Check ArcGIS Enterprise Life Cycle | Esri Support, ArcGIS Pro Life Cycle | Esri Support, and similar support pages to see what historical release dates have been.
