Fred Barbash of the Washington Post incorrectly reported on Day-to-Day on NPR today that the decision did not address whether online sales of wine might encourage underage drinking. The Court did indeed discuss that issue:
The States, aided by several amici, claim that allowing direct shipment from out-of-state wineries undermines their ability to police underage drinking. Minors, the States argue, have easy access to credit cards and the Internet and are likely to take advantage of direct wineshipments as a means of obtaining alcohol illegally.
The States provide little evidence that the purchase of wine over the Internet by minors is a problem. Indeed, there is some evidence to the contrary. A recent study by the staff of the FTC found that the 26 States currently allowing direct shipments report no problems with minors’ increased access to wine. FTC Report 34. This is not surprising for several reasons. First, minors are less likely to consume wine, as opposed to beer, wine coolers, and hard liquor. Id., at 12. Second, minors who decide to disobey the law have more direct means of doing so. Third, direct shipping is an imperfect avenue of obtaining alcohol for minors who, in the words of the past president of the National Conference of State Liquor Administrators, "'want instant gratification.'" Id., at 33, and n. 137 (explaining why minors rarely buy alcohol via the mail or the Internet). Without concrete evidence that direct shipping of wine is likely to increase alcohol consumption by minors, we are left with the States' unsupported assertions. Under our precedents, which require the "clearest showing" to justify discriminatory state regulation, C & A Carbone, Inc., 511 U. S., at 393, this is not enough.
Even were we to credit the States’ largely unsupported claim that direct shipping of wine increases the risk of underage drinking, this would not justify regulationslimiting only out-of-state direct shipments. As the wineries point out, minors are just as likely to order wine from in-state producers as from out-of-state ones. Michigan, forexample, already allows its licensed retailers (over 7,000of them) to deliver alcohol directly to consumers. Michigan counters that it has greater regulatory control over instate producers than over out-of-state wineries. This does not justify Michigan’s discriminatory ban on direct shipping. Out-of-state wineries face the loss of state and federal licenses if they fail to comply with state law. This provides strong incentives not to sell alcohol to minors. In addition, the States can take less restrictive steps to minimize the risk that minors will order wine by mail. For example, the Model Direct Shipping Bill developed by the National Conference of State Legislatures requires an adult signature on delivery and a label so instructing on each package.
Update: To make the answer to the question in the post's title clear: No.