There's still a possibility of Nintendo releasing an update on March 31st, it's not midnight yet here in Europe and it'll be hours more before it's April 1st in America, but I'm kind of doubting that there will be an update to support My Nintendo, when, like I said previously, I received platinum points on My Nintendo for signing into eShop on my Wii U. It seems like everything is already in place for their new points system, or it only took updating the server side to add support for it. Unless there is something else they need to update the eShop for that has nothing to do with their points system.
The OP was based on a post from Nintendo that there would be an eShop update on March 31st. This is not inaccurate, since there were plenty of things updated (or created) on eShop today, I believe it was just misunderstood what the nature of that update would be. Nowhere was it mentioned that it would require a firmware update.
