Untrue. Ottomans by that time were only a bunch of sheeplovers that could be easily beaten into goo. Also, Byzantines weren't doomed to lose western Asia Minor - actually, considering the weak turkish states of that time, it is suprising the way things turned in OTL. All Byzantines needed was to keep their primary focus in Asia, not Europe. And that's where Laskaris come through - one of the reasons that Paleologi left Byzantine Asia Minor to fend for itself was because that area was Laskaris-supportive...
Indeed.
If we would have been talking about John V Palaeologos, then Matthais would have been right, but the situation was very different during the reign of Theodore II Lascaris.
And in fact, the Ottoman state didn't even
exist at this point, and especially at this point in history in the Turkish parts of Anatolia, even the slightest changes in the local political situation could easily result in butterflies that have serious effects on future political developments.
At this point, the Byzantines could easily have played the Turkish frontier principalities off againest eachother and made sure that none of them became powerful enough to become any kind of serious threat -
if they would have at least
tried to do so.
What's more; if the Laskarids remain in control of Byzantium at this point, then the absolutely disastrous reign of Andronikos II will be butterflied away, which will make *a lot* of difference, even
if the successors of Theodore II Laskaris are mediocre at best.
Andronikos wasn't just a bad emperor - he was a
spectacularly bad and uncapable emperor, who also ruled for no less than
46 years.
During Andronikos' reign, the empire was basically ruined by a combination of civil wars (that could have been avoided), overtaxation, general mismanagement, and various solutions that turn out to be even worse than the original problems.
Andronikos also dismantled the Byzantine fleet and army, and decided to rely on the Venetians, Genoese, and European mercenaries like the Catalan Company, instead - which really paid off, I might add, as the Catalan Company soon rebelled, resulting in
yet another civil war.