Unfortunately, your final output would still be rather large if you chose to export in an uncompressed format. However, it may be worth it for future projects.
In my opinion, your best bet to save quality would be to export your After Effects animations in QuickTime or AVI Lossless (which is a preset in the Render Queue in After Effects) and import the Lossless .mov or .avi into Adobe Premiere. This way, your animations won't experience an initial compression to a lossy codec like .mp4 out of After Effects and another round of compression when you upload to YouTube. At that point, you can then output your final videos from Premiere in an H.264 video file (with a bitrate of 50Mbps or higher) for YouTube. Lastly, you could then save the Premiere Pro project file, After Effects project file, Lossless animation exports from After Effects, and the original .mp4 you recieved on Blu-Ray, a hard drive, or LTO for future distribution while losing only a minimal amount of image quality. Though you will get an additional round of compression when turning your finalized videos into H.264's, it will make uploading to YouTube much, much faster with a minimal loss in quality. Otherwise, if you try to upload a Lossless video to YouTube, it could take an entire day or more!
Hopefully that helps!