No, but it's better if they do. Rather than saying a 21st century film or book reflects Romantic thinking, it's better to find something from the era and then you don't have to justify your choice as much -- it's right there in black and white that the text is from that time. My Ext.1 teacher was saying that even Romantic paintings are good texts because you're not just exploring the depth of the literature, you're exploring the historical period, and paintings can actually express alot.
Resonances of Romanticism are evident in so many modern texts, and if you explore those properly and in depth, link them back to social and political paradigm shifts, analyse the features of Romanticism properly, then you can do modern texts. The thing with Romantic era texts is that everyone is going to do the obvious. Choose something unique and intelligent and make yourself an expert on it.
Edited to add what I just also thought of:
What defines the beginning and the end of the Romantic era? Commonly accepted for a beginning date is 1798. Why? The Publication of
Lyrical Ballads. But who defines the beginning? Who defines what is included in the Romantic canon? And when did the term Romantic come to exist as a critical, evaluative term? It's all about
hegemony and
power. So even if you're doing a Romantic era text and you say you don't have to justify your choice, you're wrong. You do need to justify your choice.
