Why would some cross an F5 with an F2?

Hi jacking this thread to ask a breeding question - was the closest thread I could find without making a new one.

When you use two sister phenos (s2’s) - both used to produce seeds with using the same male - when you then bring it the offspring together from seeds made with those 2 sister plants… would the following seeds be f2’s even tho they were made from two ‘different’ moms - but being sisters.

What would these seeds be called? I’m assuming f2’s genetically?