The article in the OP didn't explain why the republican electors would risk jail with such a stupid maneuver. A google search produced the other side of the story, it's not as sinister as the one in the OP, but it does explain why no charges have been filed.
“If President Trump had ultimately won the state of Wisconsin, Republican electors would have needed to have met on that date, time and location in order for the results to be certified.
This meeting was held at the advice of legal counsel, just in case the Trump campaign’s legal efforts resulted in the campaign’s favor.
If President Trump had ultimately won the state of Wisconsin, Republican electors would have needed to have met on that date, time and location in order for the results to be certified.
This meeting was held in accordance with precedent.
In the 1960 presidential election, it initially appeared that Richard Nixon had won by 141 votes in that state of Hawaii. The razor-thin results prompted two recounts.
While the recounts ran their course, Democrat electors met to cast their votes for John F. Kennedy in case Kennedy emerged as the winner following the recounts.
After two recounts, it was revealed that President Kennedy won the state of Hawaii. Because the Democrat electors had met, Hawaii was able to award its electoral votes to John F. Kennedy.”