At the risk of more equine abuse, here’s the Store support copypasta:
“The bands themselves are made to stretch over time but not in an exaggerated way, instead they accommodate to the user's wrist becoming standard and not too tight/loose, so overtime it doesn't even feel like it's there, this is for both varieties.
The silicone one has the note added as silicone as a material can stretch but sometimes it can be quite harder, it depends overall on the way it was manufactured, whereas the braided naturally stretches with no complications.”