Juan III could marry his Portuguese cousin ITTL, perspectice of future Iberian Union would still be tempting. Charles II's Burgundian kids could partially take roles of OTL Philip's kids (Burgundian-Iberian match?).
Also, in such situation Habsburgs would be more concerned about Central Europe than about Iberia, so Mary + Louis match is priority, but Eleanor + Sigismund is also very likely.
Also, in such situation Habsburgs would be more concerned about Central Europe than about Iberia, so Mary + Louis match is priority, but Eleanor + Sigismund is also very likely.