If you do it that way, then you will wind up deleting the apps from the card as well. It is a bit of a flaw as the phones show them as "Internal" once on the card. The reason for this is the SD card must be formatted to allow for apps to turn off of it. This requires a phone that is running Android "Marshmallow". If you aren't running that, or can't upgrade to it, then it won't work. Also, your phones manufacturer has to have not limited this option on the phone. Sadly sometimes the do.
If you are running "Marshmallow" and if your phone does allow for converting the card from "External" to "Internal" storage, then even though you are moving items over to the card, it will still say it is "Internal". Which can lead the system to delete the copy on the card and the copy not on the card. It is a bit of a pain. To avoid that, at least with apps you don't have things in you want to save, you can try uninstalling the apps from the phone, then having them downloaded and installed directly to the SC card, once the conversion has been done. Below is how to do the change.
How to turn external SD card into internal storage on "Marshmallow".
NOTE: Please be sure you start with a blank SD card. It needs to be blank because when the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device).
1. Go to device “Settings”, then select “Storage”.
2. Select your "SD Card", then tap the “three-dot menu“ (top-right), now select “Settings” from in there.
3. Now select “Format as internal”, and then “Erase & Format”.
4. Your SD Card will now be formatted as internal storage.
5. Reboot your phone.
NOTE: If you don't reboot the phone, many things may not work correctly, so make sure you do.