No. It's very simple, once airbourne forget about "planning minima." Just put it out of your head, "planning" minima are always left on the ground.
Got to disagree there, CamelhAir. Imagine you're flying to London, and Amsterdam is your alternate. If you are enroute and receive forecasts that indicate London will be below Cat III minimums and Amsterdam will be below Cat I minimums, you cannot continue to London unless you find a new alternate that will be above
planning minimums. (OPS 1.340 b, as quoted above)
Back to the original question, which was, if I'm reading it correctly and using eltazar's example, as follows: destination Frankfurt, which will be above limits. You want to use Munchen as your alternate, but you can't, so you use Paris. You arrive over Frankfurt to find that you have to hold, and then reach the fuel level required to divert to Paris. Is it legal to hold a little longer, and then go to Munchen if the weather there is below Cat I? Should you thereafter have a problem, I think that the lawyers at your trial would point to OPS 1.340 (a) (2), and say that when you chose Munchen as your new destination alternate, that constituted in-flight replanning and therefore required planning minimums.