EDIT: Date 10/3/2020 @ 8:11PM -7:00 Arizona US time
Issue:
As soon as minecraft loads, it does not find my microsoft account. I have changed the email account to my current and new everyday email on microsofts website and made approptriate changes on my PC as well. I have uninstalled and reinstalled Minecraft to no avail. My xbox gamer tag shows when I launch the app on my PC but after I hit the "Let's Play!" button, it imediatly crashes. Minecraft was working just fine yesterday and after the email merge it seems that it will not let me play =C. I can see that Minecraft is still within my purchases on Microsoft store, I can also see the minecoins added after. The game was purchased last year. I have also removed then re-added the email account to my PC and still crashes after clicking "lets Play!"
I cannot find any resources here on the Mojang bug report website or anything that matches my specific issue. If anyone has any suggestions besides the steps I have already taken I would be greatful!
Linked issues
Comments 5

So are you able to play Minecraft without it crashing now?
No @Mod GoldenHelmet. I also have not heard back from the support ticket made through minecraft.help. :net: which is what a Microsoft support agent suggested. It has been 3 days and have not heard back and I am aware that with the current covid19 crisis, wait times can be much longer. Seeing as after the email account was switched to the new email account, It is almost like Mojang is not able to communicate with my Microsoft account. At this time, no solution is found. WIll update the previous ticket to reflect on this one.
I have found the solution to this issue and could help many others who run into this issue if you are migrating email accounts.
SOLUTION: Assuming you are on PC, make sure that you have logged out and completely removed your microsoft profile from your PC. Log back into your PC with your microsoft account and make sure that on the microsoft marketplace your new email is shown and the same goes to the xbox companion app.
My issue: after a breif conversation with a microsoft tech agent on chat, we were able to find out that I was missing the (Xbox Companion App) which corralates all API's purchased on your microsoft profile to the games or in my case Minecraft to login and work properly.
All is well, back to building!

Reopening to resolve as duplicate of MCPE-63540.
Edit: This issue remains unsolved and still cannot get passed the Login page as it crashes when clicking the "Lets play" button.
Microsoft contact made: After opening a chat support with an xbox ambassador, due to the fact I changed the main email to another email account on Microsoft, I will need to wait for anything to work. So Microsoft is slow in the account verification department.
Semi-Solved answer is (This did not work issue still persists): You must wait 24-48HRS, in my case 48 hrs because Microsoft uses shamefully slow methods of verification even though I verified everything on my end. Tsk Tsk slow microsoft, not only is windows 10 a disgrace, but so is your verifications method. Sad.