If I may ask, was there any particular reason for ditching XEmacs
compatibility?

I have no intentions of starting an "edition war" and pre-emptively ask
for forgiveness should this inadvertently occur.

On 26 May, Nicolas Goaziou wrote:
> Hello,
> 
> I finally did the grunt job and removed all XEmacs compatibility in the
> code base (development branch).
> 
> On the Emacs side, the following functions are now considered obsolete
> and may trigger innocuous compilation warnings:
> 
> - `org-add-hook',
> - `org-decompose-region',
> - `org-detach-overlay',
> - `org-file-equal-p',
> - `org-float-time',
> - `org-indent-line-to',
> - `org-indent-to-column',
> - `org-looking-at-p',
> - `org-looking-back',
> - `org-match-string-no-properties',
> - `org-propertize',
> - `org-re',
> - `org-select-frame-set-input-focus'
> 
> The next step is to remove compatibility code for Emacsen older than
> 24.3 release, if anyone feels like spending some time on it during
> a rainy day.
> 
> Regards,
> 
> -- 
> Nicolas Goaziou                                                0x80A93738
>