Dear JasonKL8,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
As per the description you have shared, I understand Spell Check does not display suggested words in new Outlook for Windows as it is in legacy Outlook.
We do understand your concern here, but after thorough testing and consultation, it’s been concluded that the feature you're inquiring is not yet available in new Outlook. However, thank you for bringing this to our attention, your concern is very meaningful and reasonable. Since New Outlook for Windows is still in active development, we will surely raise your concerns to our Product Development Team and hopefully this can be included in the future updates. In the meantime, we sincerely recommend you post your concern as an idea to our Outlook in-app feedback site Contact support and provide feedback within the new Outlook for Windows - Microsoft Support

Our Product Development Team are committed to enhancing the customer experience by continually examining suggestions to include in the design and development of future product upgrades based on your suggestions. Hopefully your suggestion will help many users in the future.
Thank you for your time and understanding. For other questions, feel free to add your post in the Microsoft Community team.
Stay safe and healthy. Have a good day!
Sincerely,
Simbarashe | Microsoft Community Moderator