I'm concerned in the same way, PD, but more so. That's one reason I haven't been on the thread about the movie.
The real danger is the new film turning out to be something different from DS and very popular, with its own audience and fandom, who might sweep in and overwhelm the TV series fandom. The film fans may take a look at the series and laugh. I'll remember one fan of later Star Trek who called original Trek "unwatchable" because of the lack of CGI. There's a general tendency to laugh at anything for being old now.
Worse yet, maybe, there may be a big "middle" group of fans who love both the film and series, even if the film is not in the spirit of the series at all, to many others. Then it becomes impossible to keep the new version of what DS is (now) supposed to be, in people's minds, from shifting the fandom, and sites like this.
Take Doctor Who, a show and fandom that meant a lot to me for years. The new series, which keeps shifting more and more away from everything I liked classic DW for, now defines what DW is to people. The classic 1963-1989 show is just something in the misty dawn of pre-history which led up to new DW. Staying true to the old show isn't a priority. All this distorts fandoms.