I've actually been thinking about this exact question a lot recently. And I can't come to any other reasonable answer than "yes".

Calling us a seed is really accurate. We've made a lot of progress as humans since we came down from the trees and invented fire and tools, but we're still just a tiny blink of the eye in a galactic timescale. There's a decent chance that in hundreds or thousands of years there will be hundreds of billions or trillions of humans spread out all over the solar system and possibly beyond. I can't think of any moral reason not to give those people some moral weight. It doesn't even have to be the same as the moral weight we give to a life today, even if there's some uncertainty, the vast numbers and timescales involved mean we need to consider the distant future as an import factor in choices we make today.