No, it’s small. From @TabloTV on Facebook
the overall number of Tablo users with multiple units is low
All the facts have been posted in the blog and on FB.
We debated it a lot internally, but if we wanted to start rolling out new paid services it just wasn’t possible with the current account structure.
This wasn’t an “o crap we made a mistake” moment. They clearly spelled out the fact that they’re changing what they already sold to existing owners, they even gave a nice animated GIF as an example of how it’ll affect existing owners.