These changes, if true, significantly reduce the value proposition of the program.
Loosing partner lounge access reduces the value proposition of flying on partner airlines; living in a major market non-DL hub (SFO) flying AF or KE is hugely important for second tier cities. UA, by comparison, provides access to almost all Star Alliance lounges. Also, AA has recently increased reciprocal privileges for Admirals Club members flying on AA.
I can understand limiting guests, increasing revenue per guest by charging more/limiting credit card holders, etc. but limiting access when flying on a non-partner airline seems pretty draconian.
Also----I'm pretty sure that Amex Plat/Cent customers already must be flying DL.
Hope that this article is inaccurate.