This information is available in `data-parsoid`,
Π01 class
```
<meta property="mw:PageProp/displaytitle" content="Π01 class" data-parsoid='{"src":"{{DISPLAYTITLE:&Pi;<sup>0</sup><sub style=\"margin-left:-0.5em\">1</sub> class}}","a":{"content":"Π01 class"},"sa":{"content":"&Pi;<sup>0</sup><sub style=\"margin-left:-0.5em\">1</sub> class"},"dsr":[0,78,null,null]}'/>
```
However, `data-parsoid` is stripped for template generated content.
'Til Death
```
<meta property="mw:PageProp/displaytitle" content="'Til Death" about="#mwt4"/>
```
See the expected results in,
https://en.wikipedia.org/w/api.php?action=query&prop=info&inprop=displaytitle&titles=1983+World+Artistic+Gymnastics+Championships%7C%27Til+Death%7C%CE%A001+class&format=jsonfm
The current content is only useful for stuff like,
IPhone
```
<meta property="mw:PageProp/displaytitle" content="iPhone" about="#mwt3"/>
```