Smart move from Microsoft to fool consumers once more. Even though the pass is $7 cheaper now, it's still $7 more expensive than it was several months prior. Removing Call of Duty will see them getting paid massively at retail once again, so any freeloaders who choose not to renew the pass even at the cheaper rate, Microsoft will still rake the money in from unit sales of the game which will comfortably exceed any lost revenue at the original pass increase rate.
Arguably $23 a month without a flagship title like Call of Duty is an outrageous rip-off in itself. The only consolation is that the games on the pass, particularly the indie games may actually get to make a better share of income without COD absorbing it all. Some indie titles were probably lucky to walk away with 30 cents an install on products that would cost £20 at retail.