spandafter.tex

%!TEX TS-program = lualatex
%!TEX encoding = UTF-8 Unicode
%!TEX spellcheck = en-US
\documentclass{article}

\begin{document}

\makeatletter

% make 🍣 \expandafter again
\catcode`🍣\active
\let🍣\expandafter

% test
\texttt{\meaning🍣}
\def\xAB{AB}
\def\xExchange#1#2{#2#1}
🍣\xExchange\xAB\relax

\end{document}