The answer is NO.
The reason is provided in the flexbox specification:
In a multi-line flex container, the cross size of each line is the minimum size necessary to contain the flex items on the line.
In other words, when there are multiple lines in a row-based flex container, the height of each line (the "cross size") is the minimum height necessary to contain the flex items on the line.
Equal height rows, however, are possible in CSS Grid Layout:
Otherwise, consider a JavaScript alternative.