6500 years is comparable to the time scales of planetary nebulae, so it may not even exist anymore. I seem to recall reading that there was a supernova near the pillars, which may have destroyed them. If this hypothesis is true, we should expect to see the destruction in about 1000 years.

Note that these simple calculations work because it is so close to us. As you get to distances comparable to the size of the observable universe, you have to start respecting GR to get the right answers.