If other clubs don't have wide enough step treads or enough facilities or exists to cope with safe standing at a high ratio (i.e. nearly double capacity in some sections) then you would steal a march. Going up to 1:1.8 won't be a matter of simply installing rail seating and selling 80% more tickets. A lot of clubs might not be able to do it easily. What you're doing is baking in the possibility from the start. Taken at face value, that's smart.
I am a bit cynical about this though as it comes off the back of a lot of people being unhappy with 52k. Saying "we'll design it to get to 62k if the law changes" is smart, but also nicely convenient. Is there actually any evidence the law will change to allow standing at high ratios? Have the club simply given themselves a way of placating fans about capacity now, whilst at the same time giving themselves a way of passing the buck if the stadium never goes above 52k in the future?