It's more correct than it was.
Technically you are outputting 5.1, but only 2.1 channels will have any sound in them. That's what's necessary. C, SL, SR will be silent. So practically you're outputting 2.1. Whether you want to think of that as 2.1 or 5.1 is up to you.
But as far as correctness, I would question the subwoofer crossover point you have selected. You will have to decide that based on what your main Left and Right speakers can do. Personally and in my experience, 250Hz is an extremely high frequency to be sending to a dedicated subwoofer. That's almost middle-C. Only if your main speakers are extremely small and bass-deficient would that be remotely correct, like for a sound bar or micro-satellites. A more common crossover point would be between 100 and 150Hz if your main speakers are small. For medium to large speakers, crossover points of 50-80Hz are normal. Crossing over at 250Hz will affect your stereo imaging, because you can definitely localize sounds at that frequency.
But that's between you and your speakers. You should check your main speakers' frequency response and set the crossover point appropriately.
I'll also mention it's not desirable to resample everything to 192 unless you have to. It is better to use integer multiples. So for example, it is better to resample 44.1kHz to 176.4kHz instead of 192kHz, since 176.4 is an integer multiple of 44.1. There will be a small quality difference, although whether you will be able to hear it or not, I don't know. If your output device support 176.4kHz, use it.
Good luck...