It honestly highly depends on what they'll do with the microtransactions. If it's the "Pay 0,99 or watch ads X amount of times to get a different color!'' type, it's still annoying, but not as bad as it technically could be.
I think a big reason why Flappy Bird got so popular was also just the simplicity, but adding more modes and skins is just the way to keep the current phone game market alive alongside microtransactions.
But hey, it's important to remember that this is likely targeted towards the newer generation.
I doubt it'll flop purely because of the transactions; in fact, that's what's going to keep people engaged in it for longer, if they're implemented okay enough.
