EA_Cade said that they are already looking into these issues which they have also kept Origin from switching over to the EA app until further notice. He has also shared the Origin download link for anyone wanting to go back to Origin in another thread.
Edit to add a quote from EA_Cade.
https://forums.thesims.com/en_US/discussion/1005204/ea-app-required-now#latest
"EA_Cade;c-18211028" wrote:
No worries at all.
We are also currently looking for EA app error reports ID's for the issues players were seeing with Sims 2 Ultimate Collection showing as Double Deluxe or as a ZIP file instead of the normal game install.
Additionally, we are also seeking report ID's for players having issues with the Sims 3 store content not installing.
If you can provide these ID's (or any other issues) please report them on Answers HQ here so that hopefully we can get these errors corrected before migrations are resumed in the future.
And here is the quote that EA_Cade has the Origin link for anyone who wants to go back to Origin for the time being.
https://forums.thesims.com/en_US/discussion/comment/18212625#Comment_18212625
"EA_Cade;c-18212625" wrote:
"Horrorgirl6;c-18212620" wrote:
"Bluegayle;c-18212618" wrote:
@Horrorgirl6 Since I posted that I returned exclusively to Origin. It was hit and miss for awhile but seems to be loading all now. However Origin has been acting up a bit again so I may get an unwelcome surprise next time I go in to play 3.
Do you have a link that I can download origin ?
You can use this link while Origin is still available.