I thought it might be helpful to illustrate the potential impact.
Before:
Tier 1: 3 attractions - Saucers, Slinky Dog, and TSMM
Tier 2: RnRC, ToT, Star Tours, plus some shows
Attendance: 20,000 per day, half onsite
Tier 1 FastPasses available per day: 1200 x 3 x 12 = 43,000
RnRC, ToT, Star Tours FastPasses available per day: 1200 x 3 x 12 = 43,000
Assumption: all onsite visitors get their 1 Tier 1 FastPass and RnRC and ToT as their Tier 2
33,000 Tier 1 FastPasses available to offsite visitors and season pass holders (43,000 - 10,000)
Note:
23,000 RnRC, ToT, Star Tours FastPasses available to offsite visitors and season pass holders (43,000 - 20,000)
After without tier adjustments:
Tier 1: 3 attractions - Saucers, Slinky Dog, and TSMM
Tier 2: RnRC, ToT, Star Tours, plus some shows
Attendance: 40,000 per day, half onsite
Tier 1 FastPasses available per day: 1200 x 3 x 12 = 43,000
RnRC, ToT, Star Tours FastPasses available per day: 1200 x 3 x 12 = 43,000
Assumption: all onsite visitors get their 1 Tier 1 FastPass and RnRC and ToT as their Tier 2
23,000 Tier 1 FastPasses available to offsite visitors and season pass holders (43,000 - 20,000)
3,000 RnRC, ToT, Star Tours FastPasses available to offsite visitors and season pass holders (43,000 - 40,000)
After with tier adjustments:
Tier 1: 5 attractions - Saucers, Slinky Dog, TSMM, RnRC, and ToT
Tier 2: Star Tours, plus some shows
Attendance: 40,000 per day, half onsite
Tier 1 FastPasses available per day: 1200 x 5 x 12 = 72,000
Star Tours FastPasses available per day: 1200 x 1 x 12 = 14,000
Assumption: all onsite visitors get their 1 Tier 1 FastPass and RnRC and ToT as their Tier 2
52,000 Tier 1 FastPasses available to offsite visitors and season pass holders (72,000 - 20,000)
No Star Tours FastPasses available to offsite visitors and season pass holders (14,000 - 40,000)
I put this forward as a first draft analysis. I'm sure that together we can update it with better numbers for attendance, ride capacity, anticipated hours, percentage onsite vs offsite/season pass to get us some additional insight into why Disney might have thought this was a good idea. My numbers look wrong because they seem to show that even with an anticipated attendance of 40,000 and 70% of capacity given out as FastPasses, there will be more Tier 1 FastPass capacity than there will be demand for it.
I think it's dangerous to draw conclusions from a preliminary analysis, but the above numbers *might* show that the retiering helps offsite visitors and season pass holders. The only reason I can come up with for this is the idea that onsite visitors will already be getting the opportunity to go on everything they want during the extended EMH hours, and offsite guest satisfaction would be too low if onsite guests were to end up monopolizing the FastPasses after EMH after getting to ride on everything during EMH anyway.
Looking forward to everyone's adjustment of the numerical analysis or overall critique.