The news that Glenn and Abraham were murdered by Negan was enough to push her into action, which will likely in turn push Ezekiel into joining his forces with Rick and Co. If all goes well, the characters will be able to avenge Glenn’s death in the not-too-distant future.
Of course, this is The Walking Dead where nothing ever goes entirely well, but we can always hope.
Glenn’s legacy also just directly impacted Carol’s story.
She’s spent the majority of Season 7 isolating herself on the outskirts of the Kingdom, and even a reunion with her pal Daryl wasn’t enough to motivate her to rejoin the fight.