Programmatically delete an annotation.

Open the vdp model.

vdp

To get the handles for the annotations in the model, use the find_system function.

h = find_system(gcs,'FindAll','on','Type','annotation');

To identify the annotations, query the text inside the annotations.

get_param(h,'PlainText')

ans = 2x1 cell
    {'Copyright 2004-2020 The MathWorks, Inc.'}
    {'van der Pol Equation'                   }

To delete the title of the model ('van der Pol Equation'), get the Simulink.Annotation object that corresponds to the second handle.

a = get_param(h(2),'Object');

Delete the annotation from the model.

delete(a)