If you are, you should demand to be assigned a Garden View room (that is, a room that was classified as Garden View at the time you booked), or else to be refunded the difference in nightly cost between the Standard and Garden View rooms (again, as it was at the time you booked).
Disney can't sell you one view category and assign you another without compensation. That's fraud.
We'll be in the same situation (although at the Yacht Club) in August. To my great dismay, I've called Disney three different times about this, and gotten three different answers. One CM told me that all the Garden View reservations had already been converted to Resort View on their end of the system, and that because room assigners have no idea when or what you originally booked, they'll put you in anything now considered Resort View, including a number of rooms that used to be considered Standard View (and by the same token, they won't consider putting you in any of the former-Garden-View rooms - that is, ones facing the resort's "quiet pool," that have now been converted to Water View. At YC, that was almost HALF of the Garden View inventory!). The second CM I spoke with said the exact opposite -- that rooms will be assigned based on the inventory and room type that you originally booked, as it was when you booked it, so the only rooms we could get would be those that were Garden View prior to the change in names. The third CM I talked to put me on hold to consult with "higher-ups in Guest Services," and told me that even Guest Services has no idea exactly what the e-mail to guests meant when it said we'd be in the "same category" we booked, and had not figured out the logistics of how that promise might be fulfilled, and that I should "call back in June or July" when there might be some concrete answers. (!??!)
So I'm being cautious. I took screen shots of maps of all the YC rooms with their current (Standard/Garden/Water) designations, so that when we get assigned a room, we'll know what we're actually getting before we even look out the window, and can approach the front desk to politely request a change, or a credit, if we're given a room that's a downgrade from Garden View, as that category was defined at the time of booking.