The above video demonstrates that when deleting the connected node and then undoing the deletion the inputs for said node revert to their wildcard state, as if the node was unconnected and not inheriting the properties of the node it is connected to.
This causes a minor issue in the case of needing to enter values manually e.g. typing in strings; the aforementioned action becomes no longer possible as no input fields are present.
Reconnecting the node or connecting another node of a valid type into the node’s input will restore the inputs to their correct type.