In reality that's a practice that should already be done though. Use of tags for content should be able to tell you what you're getting into. Normally people have a pretty good idea about what they're getting into already when consuming content.

Saying 'Rape trigger warning' literally only just makes somebody who has a trigger regarding rape immediately anticipate a trigger even if they decided against consuming the content. I've pulled the most succinct evidence below.

Response affect Most of the empirical inquiry into the efficacy of trigger warnings has focused on emotional responses toward material accompanied by warnings (e.g., ratings of anxiety while reading passages; Bellet et al., 2018). These studies have reached mixed conclusions. Most studies (Bellet et al., 2020; Boysen et al., 2021; Bridgland et al., 2019; Gavac, 2020; Sanson et al., 2019) have concluded that trigger warnings have a trivial impact on emotional responses. Two studies found that warnings increase negative emotional reactions toward material (Bellet et al., 2018; Jones et al., 2020). Only one study concluded that warnings may reduce emotional reactions toward material (Gainsburg & Earl, 2018).

Avoidance Several previous studies have examined behavioral avoidance of material accompanied by a warning (e.g., choosing a video title presented with or without a trigger warning; Gainsburg & Earl, 2018). Several studies have found that warnings have a negligible effect on avoidance toward material (Jones et al., 2020; Sanson et al., 2019). Other studies have concluded that warnings may lead to small increases in avoidance behaviors (Gainsburg & Earl, 2018) or small increases in engagement with material (Bruce & Roberts, 2020).

Anticipatory affect A small handful of previous studies have experimentally tested emotional reactions (e.g., state anxiety; Bridgland et al., 2019) in the anticipatory period after giving a warning but prior to exposure to the warned-about content. This literature consistently demonstrates that viewing a trigger warning appears to increase anticipatory anxiety prior to viewing content (Boysen et al., 2021; Bridgland et al., 2019; Bridgland & Takarangi, 2021; Bruce et al., 2023; Gainsburg & Earl, 2018).

Comprehension Finally, other studies have investigated the way that warnings might enhance or reduce the comprehension of stimuli (e.g., scores on a multiple-choice test for factual content; e.g., Boysen et al., 2021). These studies have found that trigger warnings do not seem to impair or enhance the comprehension of educational material (Boysen et al., 2021; Gavac, 2020; Sanson et al., 2019).