You do need both. MV Cloud Archive (MV_CA) is an optional, add-on, per-device, license that is purchased separately. So in addition to the LIC-MV-xYR camera license, you also need LIC-MV-CA90-xYR for the 90-day MV_CA license. Note that you can buy as many or as few MV_CA licenses as you need, it is per device, and it is not tied to any camera's serial number, so you can move the licenses around to different cameras if you wish. And they don't have to be the same license term, meaning you could have cameras with 5 year licensing and perhaps 1-year MV_CA licenses. If you have a 100 camera deployment, you most certainly wouldn't want or need 100 MV_CA licenses, perhaps only 10 of your 100 cameras might need MV_CA licensing. Totally up to you. Be aware it's about 1Mbps per MV_CA stream to the cloud archive so confirm your current and expected usage on your Internet circuits.
Hope that helps!