Recently, Microsoft sent out a notice recommending this upgrade. However, at this time, it's not necessary to upgrade. The Basic SKU currently supports only Basic SKU public IP addresses. We're working on adding support for Standard SKU public IP addresses for the Basic SKU.
For now, you can continue using your existing Basic SKU Public IPs without making any changes. Should you need to reference the official guidance on upgrading a Basic Public IP address to Standard SKU, you can find it here: Upgrading a basic public IP address to standard SKU - Guidance | Microsoft Learn. You can also refer the Azure VPN gateway FAQs for additional details: Azure VPN Gateway FAQ
Hope this helps. If you have any follow-up questions, please let me know. I would be happy to help.
Please do not forget to "Accept the answer" and "up-vote" wherever the information provided helps you, as this can be beneficial to other community members.