Short answer to your question is No.
AVERAGEIFS is not available in SharePoint calculated column formulas.
AVERAGEA functions are available.
Returns the average (arithmetic mean) of the arguments.
Calculates the average (arithmetic mean) of the values in the list of arguments. Unlike the AVERAGE functions, text and logical values such as TRUE and FALSE are included in the calculation.
Check all common formulas available in SharePoint Lists:
Examples of common formulas in SharePoint Lists.
Also, you can show Average of a list column in SharePoint list view by settings Totals in View settings.
You can add some filters in list view based on project, priority name and maybe some date fields and show the average of column in list view.
Check this if it helps you: Creating List Views - Specify Totals for a View.