Not only the span, but also the logo etc. and it doesn't make any sense to save it in database, and even less to display it in mails and documents.
Store owners can not change the product name and price without any good reasons in most countries, that's right, but from there to saving unneeded stuff is quite a big difference Valérie.
But I guess the problem is that everything beneath the "main" span's for payment and shipment (e.g. <span class="vmpayment ...) in cart is saved now, instead of just the names.