First of all, welcome to the Foreigner fan site, new members!
I may be able to add some insight to this topic. Our Performance Center just hosted Foreigner on 2/24. As a donor and season ticket holder, I volunteered to help with all things Foreigner! In doing so, I had a little more of an inside look at how the program came together.
Our venue had been slated for Acoustique featuring Mick, Kelly, Tom and Jeff in January. Many tickets had been sold. In December, the band's management contacted the Performance Center and said that Mick was ill. The EPC was offered a new date in February with full band electric, as there were some conflicts with Michael and Mark's schedules (I assume they had some prior solo obligations). The EPC was also offered the option of canceling the show. Foreigner's management very specifically stated that Mick would not be there. Our venue sent out a flyer explaining that one of the artists was ill and the concert would be full band electric etc. They offered refunds to anyone who couldn't make the date or who was unhappy with the change. They also offered to re-seat or refund $$$$ to anyone who had seats upfront and did not want to be behind standing, screaming, rocking fans! Anyone who called in with questions was given more details! We had no problems or complaints. The die hard fans already knew Mick would not be there and the very casual fans wouldn't have really known Mick. Our show was almost sold out and we had a wonderful VIP/Meet and Greet. One of my friend's husbands said this Foreigner show was one of the best concerts he has ever been to! He has been to a lot of concerts!
@ Marcus -- your beef should not be with Foreigner -- your venue had all the information. In fact, a venue in Atlantic City canceled a sold out show when they found out Mick wasn't going to be there. I assure you, that caused way more problems than the show going on with Bruce!!!!!
Foreigner has had a lot of band members come and go, but this group of guys are all long time members since the band re-formed in 2004. (Except Mark, but he has been Foreigner's drummer off and on for years!)(Tom has been a member since the 90s!) Those of us who have been going to concerts since the re-formation feel that this is Foreigner! These are our guys -- we have come to appreciate the wonderful talent that each brings to the stage! We also appreciate the wonderful people that they are! They are all truly dedicated to putting on fabulous high energy shows that totally rock! They are true to the spirit of each song -- most songs sound even better than the original studio recordings!!! Kelly is magnificent in his vocal interpretation and delivery of each song!!!!! What more could a fan ask for than a fabulous show performed by the nicest, fan-friendly guys in the biz!!!!
I think I can say that collectively, it breaks our hearts that Mick has had health problems. We all adore him and love watching him on stage!!! He is our guitar hero!!! We are looking forward to Mick's return to the stage!!!!! However, we are so happy that Bruce Watson has stepped in for Mick! He is an excellent guitar player and Mick selected him -- so we are just fine with that! Bruce is also a super nice guy and fits in with the band.
We absolutely want the shows to continue with Bruce until Mick returns!!!!! Foreigner shows are the most fun and we would all be bereft if they canceled the tour!!!!!
By the way, I always YouTube recent concerts of any band/comedian etc before I buy tickets.
We hosted Ron White -- some people walked out because his language was "filthy and he drank scotch and smoked a cigar on stage!" Really?

? -- a glance at YouTube would have cleared that up!!!! There are plenty of recent videos showing Bruce and explaining who he is and why he is there.
Mick owns the Foreigner name and he is in charge! The Grateful Dead changed their name to The Dead because Jerry Garcia died! Queen performed as Queen + Paul Rodgers because Freddie Mercury died!
I'm sure this whole situation is very stressful for the band members! They have carried on admirably!!!!! It is up to us fans to support them wholeheartedly!
We must also thank Tom for stepping in and playing Mick's keyboard parts! Wow -- he just nails them every time! He and Michael really have their parts together finessed, too!!!
So, a big thank you to Bruce and Tom for filling in for Mick and doing a wonderful job! Another big thank you to Kelly, Jeff, Michael, and Mark for carrying on!!!! A special thank you to Kelly!!!! In addition to belting out the hits, he has taken on the role of emcee!!!!! We all love and appreciate each one of you!!!!!
Jan