Batanggenyo and Bulakenyo jokes, tonal Tagalog, and maybe diacritic reform?
The following applies more to Tagalog than to Filipino, whose phonology and grammar arguably differ enough that they make the jokes nonsensical.
What happens if we follow the custom in some Canadian languages where the glottal stop a.k.a. impít is written using the number 7? (The formal symbol for the impít looks like it in the International Phonetic Alphabet.)
That would mean the circumflex accent would disappear, so no more standard â for example. with pala7.
But that then means á and à could now mean rising and falling tone.
Yep, Chinese style. Before we say that makes no sense in Tagalog though, consider how the following dialogue defines a joke with standard Tagalog diacritics that disappears with tonal diacritics.
A Batanggenyo and a Bulakenyo walk into a boat. Guess who is who from their accent.
Q: Nakáin ka palá ng patíng?
A: Pàlà7 ay hìndì7. Ngùnì7 at nàkà7ìn akó ng patíng.
Q: Nakakáin bagá?
A: Oò. Akó, nàkà7ìn ng patíng. Kayá7 at akó, nakaká7in ng patíng. Ngùnì7 at akó, hìndì7 nákaká7in.
Q: Makakáin ngá keylanmán?
A: Ka7ilanmán akó'y hìndì7. Máka7in ka ngà7.
Q: Walá ngáng patíng na kakáin.
A: Walá7 ngà7.