Can I use Symfony components in a plugin that I want to submit to the WordPress plugin repository?
I do not want to be rejected because of the license.
Yes, Symfony components are licensed under MIT these days. They are compatible with GPL, which is a requirement of the official WP repository.
Do note that as number of plugins using common PHP components is increasing, so does possibility of version and other conflicts between them. Since WP lacks dependency management, at some point you might have to handle such issues yourself in your plugin.