%New sleeping bag

[HobbesOnTour]

There's not much point worrying about it.

a) Down withstands the compression better than the other available options (by quite a large margin)
b) You don't have any choice in the matter, beyond not doing the trip(s), which rather negates the point of buying the bag in the first place.

I don't believe I was worrying - simply asking a question. Lots of things wear out or become less effective over the course of a long tour. Sometimes forewarned is forearmed so to speak.

My current sleeping bag (synthetic) must be 5 years old now. I don't recall when I was doing my research there being a major difference between the longevity of synthetic vs down. (My previous bag was also synthetic). I specifically recall extra attention being drawn to storing down bags in an uncompressed state. I also recall the negative effects of water on down as opposed to synthetics.
Reading again on the topic it does seem that long term down lasts longer. There have also been advances in water repellent technology for the down.

My interest was piqued because the op's bag was delivered uncompressed. I'm presuming it is also stored, awaiting shipping, that way. That costs the supplier more money, so there is obviously a valid reason for it.

It seems reasonable that constant compression (and decompression) will have an effect.

 

[Gravity Aided]

It did, back in the day. We were always told by the manufacturer that long term down storage should be uncompressed. But down was notorious then for getting wet and soggy and compressing into the cells, and getting loose like a trail of breadcrumbs. Things have improved lately, but I'm still happy with the synthetics