I can provide you some information about changing products by bulk in QuickBooks Online.
Changing products by bulk isn't currently offered in QuickBooks Online. You'll need to edit and change it manually. I can definitely see how this feature would be useful. As a team with a massive roadmap, we have to pick new features based on the value they’ll add to the most users possible.
We would appreciate it if you can send feedback to our Product Developers. This will notify them that this feature would be beneficial to running your business.
We aren't able to tell when a feature will be available. We share recent happenings and future developments on our blog. Through this, you're able to get the latest news about QuickBooks Online and what our Product Care Team is working on https://quickbooks.intuit.com/blog/.
If I can be of help while working in QuickBooks, please let me know. I'll be here to help. Have a good one!