Agree with you LGS6753. Almost certainly a "journalistic mixup" and really relates to easy's announcement to start Sofia from LGW earlier this week. Besides that, Wizz already operate Sofia 4 x weekly from LTN, and that is to continue throughout the winter, so doubt they would compete.
Interesting to note that Wizz is to start Katowice flights from LGW, meaning it will serve the route from LGW, LTN & STN.