A good blog/site for details on the monthly youtube video – https://blogs.technet.microsoft.com/o365guy/

But also this article has the specific product suggestion pages

Topic Link
Access https://access.uservoice.com
Bookings https://outlook.uservoice.com/forums/314907-microsoft-bookings
Business Center https://office365.uservoice.com/forums/600793-office-365-business-center
Excel https://excel.uservoice.com
Flow https://powerusers.microsoft.com/t5/Flow-Feedback/ct-p/Feedback
Forms https://microsoftforms.uservoice.com
Connections https://office365.uservoice.com/forums/600610-microsoft-connections
Invoicing https://office365.uservoice.com/forums/600781-microsoft-invoicing
Listings https://office365.uservoice.com/forums/600778-microsoft-listings
Mix https://officemix.uservoice.com/
MyAnalytics https://myanalytics.uservoice.com/
Office 365 https://office365.uservoice.com
Office 365 Groups https://office365.uservoice.com/forums/286611-office-365-groups
OneDrive https://onedrive.uservoice.com
OneNote https://onenote.uservoice.com
Outlook https://outlook.uservoice.com
Planner https://planner.uservoice.com
Power BI https://ideas.powerbi.com/forums/265200-power-bi-ideas
PowerApps https://powerusers.microsoft.com/t5/Product-Feedback/ct-p/PA-feedback
PowerPoint https://powerpoint.uservoice.com
Project https://microsoftproject.uservoice.com
SharePoint https://sharepoint.uservoice.com
StaffHub https://staffhub.uservoice.com
Skype for Business https://www.skypefeedback.com
Stream https://techcommunity.microsoft.com/t5/Microsoft-Stream-Ideas/idb-p/StreamIdeas
Sway https://sway.uservoice.com
Teams https://microsoftteams.uservoice.com/forums/555103-public
To-Do https://todo.uservoice.com/
Visio https://visio.uservoice.com
Word https://word.uservoice.com
Yammer https://yammer.uservoice.com