Currently happening for me as well on all videos, was able to view them normally yesterday so it's happened somewhere in the past 24 hours.

Turn on for me.

They gave a little more of an extension after some eShop maintenance, under 12 hours left!

It all finally closes for good at March 28, 12am UTC.

twitter.com/NinStatusBot/status/1640218729911812097

Well it's less than this for some people but the deadline's coming right up anyway. Added some more things to the first post.

It's more of a niche thing now maybe but for anyone who still has any interest in picking up games for the 3DS and/or Wii U the time for that is nearly over as they close March 27.

Currently you cannot add money to your 3DS/Wii U eshop account however if your 3DS and Wii U Nintendo Network ID is linked with your Nintendo Account you can add funds via your Switch instead:
nintendolife.com/guides/setup-and-key-facts-for-nintendo-account-and-miitomo-preregistration#how-does-the-nintendo-account-relate-to-my-nintendo-network-id

You can read more about the 3DS/Wii U eshop's closure here:
nintendolife.com/guides/when-does-the-3ds-and-wii-u-eshop-close-nintendo-eshop-closure-guide

If you need an idea for any games to buy, here's a few vids on some that might be worth grabbing:





Edit:
Some more last minute stuff

Some 3DS RPG's:




Some recommended Fire Emblem Awakening DLC:
-The Golden Pack (easy grinding plus an item that gives you a discount at shops)
-Champions of Yore 3 (has a nice skill)
-Lost Bloodlines 2 (new class)
-Smash Brethren 2 (new class)

Some recommended Fire Emblem Fates DLC:
-The version you don't have (Birthright/Conquest) and Revelations
-Map Pack 1 (lots of good things in it)

Some recommended Fire Emblem Echoes DLC:
-The Fledgling Warriors Pack (easy grinding)
-Inner Sanctum (rare items like the nice Star Jacinth)
-Altar of the Savant (helps buff your mages)
-The Cipher Companions Pack (new characters)
-Maybe Lords of the Grave & Flight from the Ruins

Some recommended virtual Console GB/Game Gear titles (tried to aim for things not on the Switch or other consoles):
-Shining Force II: The Sword of Haiya (great bite-size strategy RPG)
-Avenging Spirit (better than the arcade one! you play a ghost that possesses enemies to control them)
-Donkey Kong for the Gameboy (aka Donkey Kong '94 - a surprising classic that builds on the arcade DK with tons of levels)
-Mega Man IV (first Mega Man game with a shop, and a well done game)
-Mega Man V (unique robot masters, also well done)
-Mega Man Xtreme 2 (different level designs and stuff to the first Xtreme which copy pasted stuff, plus you can play as Zero)
-Mole Mania (neat puzzler)
-Mario Golf & Tennis (neat sports RPGs)
-Kokopolo 3D (also a neat puzzler where you slap enemies to anger and lure them)
-Severed (an interesting first person game where you cut through enemies)

For the Wii U:
-Devil's Crush (terrific pinball game)
-Ogre Battle 64 (great real time strategy)
-Noitu Love: Devolution (good platformer)
-Startropics 2 (good lesser known sequel to the original)
-Wario Land 4 (great platformer)
-Final Fight 3 (good beat em up)