[MCM-934] Dying in the end or teleporting to the end causes game to freeze

Partner Rank: 1
Partner Team Reporting: Tetrascape
Verification Build: 1.14.2 Win10
Summary: Teleporting a player into a portal to the end immediately after spawning via a command block causes the game to freeze on "loading terrain"
Impact: "The End: Skyblock Edition" is live and broken with this bug. We are publishing a temporary fix today, however we hope to continue to teleport the player immediately to increase the immersion in the map and limit confusion for the player.
Repro Steps:
1. Create "The End: Skyblock Edition" from world template.
2. Die and see results
Repro Rate: 8/8
Observed Results: Game freezes in "loading terrain" scene for the end.
Expected Results: The game shouldn't freeze
Screenshots / Videos Attached: yes
Regression Builds: This worked up to and including 1.13.x, it only broke in 1.14
Notes: Just tested in vanilla:

1. create new world
2. /setblock ~ ~ ~5 end_portal
3. go through portal
4. fall to your death
5. repeat steps 3->4

Using these repro steps in vanilla instead of "The End: Skyblock Edition", we had a repro rate of 3/40. Because of this, we updated the partner rank from 2 -> 1 as there is no workaround.

When freezing in vanilla, 1 out of the 3 times it froze, it froze with "loading terrain" in a different scene (kind of a hazy red background, unfortunately wasn't able to grab a screenshot).