"No new access requests will be granted for the Hosted Payment SDK (HPSDK) because the HPSDK is deprecated in favor of Shopify's Payments Platform on March 31, 2022."
Does it mean all existing integrations will start to fail on April 1st 2022? Or they just don't allow new shops to install those?
The functionality will be completely deprecated at the end of March 2022 as per https://shopify.dev/apps/payments/hosted-payment-sdk
As of March 31, 2022, existing HPSDK integrations will be deprecated. By March 31, 2022, you should be done re-platforming to the new platform and impacted merchants should be ready to install your new payments app. If by March 31, 2022, you haven’t migrated to the new platform, merchants will no longer be able to install your legacy HPSDK integrations and Shopify will contact impacted merchants to help them adopt a payments app to avoid payment processing disruptions.