oh balls, I was going to apply for arrival plus in august. 
The $40k spend required to make the Arrival+ more lucrative than the DC is small potatoes for serious travelers (of course the $400 sign-on bonus blows DC out of the water). If the bonus is reduced to 5%, then the $80k spend threshold would definitely be tougher to meet. I fall somewhere in the gap there I think. I spend about $4-5k per month on work travel, and $2-4k per month on personal expenses.
For me, the Arrival+ with 10% bonus is a no brainer, and I was planning to apply in about 2 weeks when I exit the garden. With 5% bonus it's a lot less clear because some of my spend goes to other cards (like SM, Amazon store card) so I think overall I'd be right around the $80k annual spend on a general use card. Still worth it if they keep the 40k points sign-on bonus, but otherwise probably a wash for me. For true road warriors I think it's still a no-brainer if you like cash back.
Maybe they are reconfiguring to add some other perks like the Citi Premier did recently. Doesn't have to be all negative thoughts does it?
