Warum keine Deklination?

In Handling language there is also a use of “typical” without flexion:

‘typical woman, man, Karin (transverse-language, often easy to evaluate; that is characteristic for women, men, for Karin)” – Dudes

‘transverse language: (this is) typical Klaus (= this is characteristic for Klaus)
language: that was typical woman‘ DWDS

“Yes, what should I say was my sister — direct and unblown.’ Wiktionary

“Typical woman” and “typical man” are, so to speak, shortened expressions for “typical” for a Woman’ or ‘typical’ for one Man’. ‘Typee Woman’ and ‘typical’he Man” with declination has something different meaning.