Do you have some reason to suspect a greater than average susceptibility to DCS, such as recurring bouts of it? Or was the DCS incident 2 years ago the only time you ever had DCS? Was it severe or mild? As I'm not a doctor and have no special expertise in DCS, I don't know how these factors may be relevant, but it seems like they could be.
But as RainPilot pointed out, if you have been flying in a commercial aircraft (typically pressurized to about 8,000 feet of altitude) from time to time over the past 2 years since the DCS and experienced no further symptoms, it seems unlikely that your body would react differently at another 1,900 feet or so of altitude.
Yes, except you rarely work hard during a plane ride. Hiking at an altitude near 10k feet, pending on your shape, what you carry, the weather the path, how much altitude gain (collectively) etc. Some of us (certainly me) will work quite hard. Still don't think it would cause DCS, still would leave that to am expert, but it certainly is a notable difference to "plane ride".