Der Zug hat Verspätung
is an example for Nullartikel, subsection Abstrakta: you will not qualify the delay further, but just point out, that in-time does not apply. This is similar to The train is delayed.
As soon as you add additional information, the indefinite article again becomes necessary as in
Der Zug hat aktuell eine Verspätung von 12 Minuten.
Another variant of the statement would be:
Der Zug hat aktuell 12 Minuten Verspätung
This is another condition triggering the Nullartikel, since it is a measurement specification, similar to 300 g Butter, with Butter taking the role of involved substance (Verspätung in your example).
A sentence according to the same pattern as your example is:
Seine Aussage hat Gewicht.
(His statement is of importance.) You can't quantify the importance (or in literal German meaning the weight, where the corresponding unit kilograms is obvious nonsense.)
The example from your question title quite urgently requires additional clarification, since without context es gibt most often means exists; it is obvious that delays happen, so a rephrase, is recommended.