Thanks for posting your question in the Community, I also received the email and do see that the option to share the message on social media isn't available. I already reached out to our team to check and will follow up with more information on this thread as soon as I receive an update.
In the meantime, if you'd prefer to share the message now you can consider taking a screenshot and posting it on LinkedIn and other social media networks.
As a follow up regarding the social sharing option missing from the email notifications we sent out recently, we can confirm this is by design. While our year-end email is different from the regular social sharing emails we send, we can confirm that our team will consider incorporating some type of social sharing functionality in future emails.
Thanks again for sharing your experience with us and congrats on a successful year - looking forward to many more to come!