First of all, that Russ is paying Artistic to manage the stations is a non-issue. That's called an LMA, and it's required by law. The licensee must have a manager running the station as it must main control until the transfer is approved. The FCC moves at its own pace, and sales are delayed all-the-time. Even the most mundane of issues can delay a transfer.
As for the extortion charge, I don't know if what Oasis is accused of is legal or not, but, if it's true, I seem to recall it's not the first time a "pay us or we take you on" threat has been made. It seems like someone told me the old WFLZ in Tampa did this to Q-105 in 1989 before flipping from oldies "Z-93" to CHR "Power Pig 93.3." I don't recall any challenges being made to 'FLZ's license by Q-105 or anyone else.