I assume that is a misquote or that he means they won't come back for some time, (by our standards,) like 80-100 years.
Sunspots were not seen or too small too be seen during a period of several decades.
And we only have sunspot records for a few centuries of the whole 6000? years since god created the Earth!Or was it a couple billion years in which case our data sample is really small!
He means until the flux increases.
As long as the flux is too low >>>>> No Sun Spots
So it is permanent in the sense that they don’t see the Magnetic Flux Increasing but they just may not have enough historical data to forecast when it will increase again. It is likely more than 20 Years but it could be never.