The net-net of this? I'm unsure if I'll keep all of my business with you or if I'll spread it further around your *A partners. Right now when I fly to Europe, I am careful to book on UA planes on UA flight numbers. There's lots of times I fly UA where LH would be more convenient.
The problem with this part - UA still gets revenue flown on LH, so for flyers like you, this change won't impact UA. It's all about moving to non-*A airlines now, or those not covered under the ATI (AC, LX, SN, TK, US, etc.)