After uMatrix has become discontinued by it’s developer,
now also Zen Mate web firewal and adblocker extension has left Google’s webstore
as it’s developer(s) decided to discontinue it.
Is all this because Google Chrome and chromium browsers soon plan to offer a far more resitricted extension API?
Less room to block, tweak and tinker for end-users, more preferred tracking and ad-launching coming our way.
Sign of the times.
polonus
Sounds like an assumption. 
Hi bob3160,
I cannot confirm what you say as final, as the new extension API has been announced
to arrive sometime in the forthcoming future, but has not materialized yet.
It was said the total amount of items to be blocked from a chromium blocker extension,
would then be restricted to around some 17.000 items,
which is far too low for a full blown ad-blocking extension to properly function.
So one would have to let quite an amount of preferred ads through 
to get at that restricted number.
So when that situation arrives ad blocking can only be used through external means,
ike adguard for instance or that kind of external software.
Indeed assumptions, as you state, but not assumptions right out of the blue.
polonus