You are correct if you talk about vanity urls in general but in AEM, you could achieve both use cases - resolution and redirection as applicable per requirement.
Try below configuration & see it yourself. If you turn on redirect checkbox, it adds sling:redirect property on the content page i.e. it becomes a server side redirect maintained by content author. Use /vanity_urls and /filter configuration in dispatcher and you should be good.
First request would go to publish server for redirection if its not cached and subsequent requests would be resolved by dispatcher itself to redirect and serve the cached content from dispatcher.
1) Configure vanity url in content page and activate
2) Configure /vanity_urls and /filter in dispatcher - Configuring Dispatcher
3) Download vanity urls component from package share and install it on publish server - https://www.adobeaemcloud.com/content/marketplace/marketplaceProxy.html?packagePath=/content/companies/public/adobe/pack…
4) Test your use case and validate from dispatcher logs
I had tested the same in the past and I think it would work fine for your requirement. I can find dispatcher logs to share, if you are interested.
