Your active licenses under a perpetual licensing model will continue working, and Hex-Rays will continue providing support as long as you renew your support periods.
However, you will not have access to IDA Pro 9.0 under perpetual terms. IDA Pro 9.0 will only be available under subscription licensing terms.
You will have the option to migrate the perpetual license to a subscription-based licensing model whenever you want, in order to have access to IDA 9.0 (sales@hex-rays.com).