I am going state some of the basic principles of etiquette, and then try to show you how they connect together, so that the answer to your question becomes obvious. At the very least, it will be obvious to me 😉 Those of you who dislike 500-word posts should probably hit the “back” arrow right now.
It is always in bad taste to be phony or pretensious. So, whatever etiquette rules you follow and whatever style of entertaining you undertake, should have at least SOMETHING in common with how you live your daily life. Renting chairs and china for your wedding, because you rarely entertain two hundred at a time, or buying a dozen tiffany-blue banquet cloths because that’s cheaper than renting and then re-selling ten of them because you’ll only ever use two in your day-to-day entertaining, that’s fine. But the most elegant and gracious party is the one thrown by the hostess who has all her various linens and china and service pieces on hand because she simply entertains in that style all the time. Your personal best-quality heirloom household goods are always in better taste than commercially-provided temporary goods.
A wedding symbolizes the start and creation of a new household — for all that nowadays most couples have been equivalent-to-married for years and the “start” of their household is already a fading memory. When you start your household, you are assumed to be looking forward to many years as a participating member of society which — in the assumption of the gods of etiquette who consider “Society” to carry importance equal to “Work” and “Family” — means that you will be entertaining. Your registry (which you do not need to share with guests, and should not advertise overtly) is your long-term plan of how to acquire the things you will need to carry out your social duties.
Those of us who give traditional gifts really want our gifts to be cherished and passed down, preferably with stories about how “Dear old Auntie Aspasia gave us those apothecary jars. She usually gives brides a soup tureen, but I had her over for dinner just before our wedding and were talking about how much I love to show off my cookies in a glass-sided jar, so she bought me these!” One way we get to enjoy our own posterity-through-generosity, is by seeing our gifts being shown off. It is quite proper and old-fashioned for the bride’s mother to hold “bridal teas” (I’m betting Brielle’s mama may have done so!) where all of the gifts received to date are displayed on long tables at the side of the room (incidentally, the fancy-lace bridal underthings, usually heavily embroidered of fine linen and completely discrete, were often laid out in the bedroom for viewing, too — while The Dress itself of course remained secret and hidden).
Fortunately for the existence of such teas, those of us who give traditional gifts also know to ship the gift to the bride’s home in advance of the wedding. It is absolutely NOT greedy to open them at once. In fact, you are supposed to do so: not only so that you can write your thank-you note before you go to bed that day, but also so that (once the bridal teas are over) the household goods can be ensconced in the couple’s never-before-lived-in-together (ahem, pretend with me, please) otherwise-empty new home, awaiting the couple’s arrival from their honeymoon. No, the gifts should not be used until after your wedding, but — obviously — your reception IS “after your wedding”. And, if no-one sends them to your home by the week before your wedding, at the last minute you can buy them (or additional ones) off your registry yourself (which is, actually, the proper use of a registry — to help you plan, not to influence your guests to give particular things) and get whatever special prices or credits the store might offer for “registry completion”)
So, in short: not only is your proposal acceptable, it is actually more gracious and more proper than using some disposable or rental item instead.