I just tried dummy bookings for London in mid-Oct, using rate code EZR, which is the code for this promo.

All the hotels offered the Welcome Back rate. Rate Details are exactly the same as pictured in the OP, except that there is no line which specifies date limits. I would guess that promo has been extended, but there’s still residual pockets of the website that still display the old date range.

Don’t think you have anything to be concerned about.