I don't known what all the fuss is about, Catholics knew about the friendship between Pope John Paul ll and Anna-Teresa Tymieniecka 20-25 years back (even I did and I go around not noticing things most of the time), and thought it was 'lovely'. He mentioned it in one of his books, can't remember which one and I don't think he mentioned her by name. What is new is the publication of some of the correspondence between the two which appears to be quite touching but not a big deal. It's normal and healthy for two people of opposite sex to have a close, longstanding friendship; for JPll, who must have been fairly isolated a lot of the time, from choice of course but still difficult for a naturally gregarious person, it must have been extremely rewarding.
Edit: I re-read the op and note that Siriam was not making a big deal out of this and said he thought it was heartwarming. I concur.