"More legacies than slots for them in their legacy chapters."

This will probably happen sooner rather than later. And if there are chapters at smaller colleges, I'm sure that the new "non legacies" (granddaughters, etc) will still get a second look.

Do you think there will ever be tiered legacies? Like, mother or sister > grandmother, but grandmother is just a weaker legacy?

I think it happens unofficially in some places already. When you have a giant number of legacies then I think some legacies get more attention depending on who they are related to and how involved or known that alumna is and that kind of influence.

I suspect that being a “chapter legacy” (i.e. grandmother/mother/sister initiated at the same chapter), might carry more weight. And the closer the "link", the greater the weight.

I was a legacy to a chapter that had more than enough legacies to fill that year's pledge class (large SEC school). My sister was an active at another chapter at a small school elsewhere. I appreciated that they gave me a courtesy invitation to Round 2, but I knew they weren't a good fit, and they agreed with me and cut me early.

Neither my sister nor I felt slighted.

My roommate had an Aunt, Mother, and Grandmother who had all been in the same sorority *at that school* and she was released from that sorority the night before prefs. Understandably, when that happened all hell broke lose. I felt bad for her and her family. Until she was really nasty to me about my clearly inferior pref list the next morning, then all bets were off.

I think it's a matter of how the sorority handles it as much as anything. But I think Mom, Sis, Grandma, Auntie and such would be best served to bring up their legacies in a way that has them thinking of Panhellenic as a larger sisterhood...