So I called them. When they eventually answered the phone, the man was not very helpful. He didn't mention travel agents at all and neither did I.
He did start out by saying "oh this is for new bookings" but when I READ OUT what it actually said on the leaflet i.e "Applicable to new AND EXISTING bookings of 7 nights and above.." he then said "oh it's existing bookings of 48 hours or less, so if you booked yesterday you could change to this offer"
I think they're making up the rules as they go along!! I'm not impressed with this. I have friends sailing in January 23 who booked their cruise around the same time as us, in the Spring. They were able to book this offer very recently. The only difference being that they went with a travel agent. So one representative tells us it's the travel agent factor and the other tells us it's the time of booking factor 🤷♀️ I don't get it.