I guess there isn't a direct relation between the version number and the EOL.
(I know we can discuss about SemVer but I guess this isn't the goal here).
Since I can't find official communciation about this I will share what I think will happen. Magento 1 will be suported until the EOL with patches and fixes to ensure those stores can continue working and being secures.
But I can't imagine a new version with new features (at least that having PHP7 support can be considered as a new feature and not a patch).
Again, this is just what I understand will happen but isn't an official answer.
(My 2 cents)
Hi,I am also new here,I wonder if there is an easy way to upgrade 1x to 2x,my developer told me it almost =rebuild my store.....