The author suggests that the change in wording is due to the source being depleted, not due to demand being met by transition to other sources.

Renewables becoming more available, or more power-providing / more efficient, or less costly - or in any other way more enticing than they are at present - does foreclose all available oil and coal and nat.gas being extracted and used. Nor does it change the demand by techno-industrial civilization to have more electrical power available this month than last month, and to have even more next month than this month.

The only sure way to prevent further fossil fuel usage is probably with the practical end of extraction and transport technologies, for even laws against their usage seems a naïve prospect (laws are difficult to implement and they change to suit Technology's advance and economic growth; monitoring everything everywhere is *for now* difficult; corruption and oversight occur, etc.).