Sure enough, both the SPG Luxury and SPG Business (public) welcome offers went down to 75k Marriott points after $3k/3 months. Lower spend, but lower points.
DISchurners PSA: If you have support links up for these cards, please adjust the offer descriptions accordingly.
ETA: Support links are still showing the old 100k Marriott points offers, but with a 10/31/18 expiration date.
I'm also noticing that I can't generate a SPG Biz link from a personal SPG card.
SPG Lux lets me refer to SPG Lux or Personal.
SPG Personal does not let me cross refer within the SPG family.
SPG Biz lets me refer to SPG Biz and SPG Personal.
I'm wondering if Amex nerfed universal/family referrals.
P.P.S. From my Biz Plat, I'm still able to generate universal referrals to most of Amex's cards (including the popular Plat, Gold, BBP, all the Hiltons), but interestingly not the SPG Lux.