Keeping your google account can be helpful if you want to follow this strategy:

1. Register on Signal using your phone number
2. Port your phone number to google voice ($20 transfer fee but free after that; additionally while its privacy sucks, google is great for security)
3. Change the settings so that every caller is sent to voice mail
4. Use mysudo and cloaked for VoIP numbers
5. Set up Signal on a new device (ideally a grapheneos pixel)
6. Use a calyx institute hotspot for data or buy a sim card with cash