The 12 men crewed Type 22 has out-lived its original design missions of (surprise) striking enemy at short range in coastal areas of China, using its stealth and remote coastal islands to hide from enemy's radar detection. These boats were degsined in early 2000s when PLAN lack modern destroyers and frigates, it was the era of type 051 destroyers and type 053 frigates, and a few "experimental/ evaluation" type 054, 051B, 052, 052B, 052C and the imported Sovremenny. Type 051C entered sevice 2 years later than type 022.
Now that China has effective means to keep hostile ships from first island chain, type 22's original mission roles is hugely diminished. To keep using these boats they have to be given a different roles, most likely defensive rather than offensive, like sea based SHORAD as suggested by Blitzo.
It can also be reconfigured for coastal ASW, seaport and naval base perimeter armed patrol, or even convert to be a large USV
If PLAN will to continue using type 22 as missile strike force, most likely deployment region would be in SCS, Penghu islands and the few Taiwan controlled coastal islands near Mainland China's shores. So there is some hope that they might still retian their original designed roles with better missiles.