Hi Sudharsan,
What happens if your resistor bridge drifts over temperature? This will affect the current through the load cell. When analyzing the current paths for sensor detection you have to consider every wire and every combination of wires. In my previous post I was referring to a wire break at both EXC+ and EXC-. If you removed the load cell entirely it would appear as though you have a load cell connected. This seems to me like a lot of effort for a single wire break detection. But it is your circuit, and you can do what you feel is best. I'm just pointing to a flaw in the concept. There are flaws with mine as well.
As far as pulling to AVDD and GND using high gain, this will saturate the PGA, but will not damage the ADS1234.
Best regards,
Bob B