The word audience is not normally used with books, which have a readership, and target readership.
I am also unclear as to why the conditional tense is used. Since it is something that happened in the past, either it did shock or it didn't shock.
I would have said: Emily Brontë’s novel ‘Wuthering Heights’ shocked people of the time.
It has been suggested that I should Google books audience, which I have done and have seen what appears. However I would still feel awkward using the word audience with regard to a book.
The OED entry for audience is vast. But all senses relate in some way to hearing. That which follows is sense 8, which might be considered relevant, but see my further edit 2 below, which draws attention to sense 7b, which has greater relevance to books.:
In extended use: those people who admire, support, or take a
consistent interest in a particular person, area of artistic activity,
idea, etc.; (also) those people who are regarded as likely to be
interested in such a person or thing.
1839 Musical World 17 Jan. 33 The choral music of oratorios..will
never want a large and increasing audience.
1914 Ann. Rep. Chicago Hist. Soc. 30 A loan exhibition of
archaeological objects..from the Chicago area..elicited great
attention. Indian Archaeology always attracts an audience.
1947 Kingsport (Tennessee) News 27 Dec. 2/5 Billy Wilder..says
there is a growing audience in the United States with a ‘good taste
for European pictures’.
1974 S. Marcus Minding Store xv. 303 While the Dior business was
directed towards the Establishment customers..Saint Laurent appealed
to a much more avant-garde audience.
1992 N.Y. Times 12 July iii. 9/4 Apple wants people to call the
Newton a..PDA, rather than a computer, since the Newton is supposed to
appeal to a much wider audience than traditional computing tools.
2012 Daily Tel. (Nexis) 29 Mar. Madonna..still has the attention
of a devoted audience.
Whichever way we look at this, I believe using audience with books amounts to an extended or metaphorical use, which refers to the book's or author's adherents.
And it does seem to me inappropriate to describe Emily Brontë as having "shocked her audience", since I am not clear that it was her audience which was shocked, so much as the wider public.
I am now persuaded, following extensive discussion in the commentary below, that the word audience has relevance to literary works. However what we have not been able to agree upon is the nature of a book's audience. The OED seems to restrict it to "people who admire, support or take a consistent interest", but according to @Edwin Ashworth other dictionaries refer to the people reached, whatever that means.
Further Edit (2)
My attention has been drawn by @Roaring Fish, to the fact that the relevant OED sense of audience is not 8, as I wrongly stated, but 7b, which deals directly with books.
b. Those people who have read or regularly read a particular text,
publication, or writer, considered collectively; a readership.
1760 B. Franklin Let. D. Hume 27 Sept. in Wks. (1887) III. 128 It
often gives me pleasure to reflect how greatly the audience (if I may
so term it) of a good English writer will, in another century or two,
a1854 H. Reed Lect. Eng. Lit. (1878) vii. 225 ‘Pilgrim's
Progress’..has gained an audience as large as Christendom.
1867 Brit. Q. Rev. July 108 Many of Keble's poems impress us with
the idea of..an audience of whom the writer was conscious.
1870 G. Meredith Let. 13 Oct. (1970) I. 428, I have an audience of
about a dozen, but if they're satisfied I am too.
1883 G. Hamilton in E. C. Rollins New Eng. Bygones Pref. 1 This
book is published with no thought of an audience.
1949 Los Angeles Times 13 Feb. (Comics Section) 1, There may be
neurotics in our audience!
1991 Utne Reader July 109/3 (advt.) The smallest village 20 miles
outside of New York City may be tiny, but it has a hot newspaper with
a sophisticated audience.
1993 Locus Oct. 4/1 I'm a writer who has an ongoing dialog with an
audience, and what that audience tells me feeds back into my work.
2008 Vanity Fair June 91/2 Like any blog site but grossly
magnified due to the mass scale of its audience and influence, Daily
Kos is a schizophrenic enterprise.