(NET) Matt 5:19 So anyone who breaks one of the least of these commands
and teaches others to do so will be called least in the kingdom of
heaven, but whoever obeys them and teaches others to do so will be
called great in the kingdom of heaven. 20 For I tell you, unless your righteousness goes beyond that of the experts in the law and the Pharisees, you will never enter the kingdom of heaven.

There are some commentators who says it signifies exclusion from the kingdom of heaven, ie. hell; whereas some argue that they remain in kingdom as least, meaning they remain saved in heaven. Which one is accurate? Is Christ giving a provision for small sins here or giving no provision at all?

For example, Daniel Whedon commentary:

Many of the best commentators understand this as signifying that he
shall be excluded. Yet such, surely, is not its exact meaning. Clearly
to be least IN the kingdom of heaven is far less than shall in no
case enter into the kingdom of heaven.

Heinrich Meyer’s Critical and Exegetical Commentary on the New Testament mentions:

He is not to be excluded (as Augustine, Luther, Calvin, Calovius,
Wolf, Bengel, and others have misinterpreted the meaning of ἐλάχ.
κληθ.), because his antinomianism is not a principle, not directed
against the law as such, but only against individual precepts of the
law, which in themselves are small, and whose importance as a whole he
does not recognise

Johann Albrecht Bengel’s Gnomon of the New Testament

Mat 5:19. Αύσῃ, shall break) The antithetical word to this is
ποιήσῃ, shall do, which occurs further on in this verse. The Scribes,
who thought themselves “great,” were in the habit of breaking them.
The same verb, λύω, occurs in Joh 7:23; Joh 10:35.—τούτων, of these)
those, namely, which follow in Mat 5:22; Mat 5:28, etc.—τῶν ἐλαχίστων,
of the least) These precepts, “Thou shalt not kill,” etc., are not
essentially the least, for in them the whole law is contained. But
they are so only inasmuch as, when rightly explained, they regulate
even the most subtile affections and emotions of the soul, and the
slightest movements of the tongue, and thus, when compared with other
precepts, appear to men to be the least.—ἐλάχιστος, least) Referring
to the preceding ἐλαχίστων. An instance of Ploce.[191] As we treat the
Word of God, so does God treat us; see Joh 17:6; Joh 17:11; Rev 3:10.
“A little” signifies “almost nothing,” whence “the least” comes to
mean “none at all” (for they considered anger, for instance, as of no
consequence whatever); cf. in Mat 5:20, “ye shall not enter.”
ἐλάχιστος; has a different force in this passage from that which ὁ
μικρότερος (the least) “in the kingdom of heaven” has in ch. Mat
11:11.—ἐν τῂ βασιλείᾳ τὼν οὐρανῶν, in the kingdom of heaven) which
cannot endure the presence of the unrighteous.—ποιήσῃ καὶ διδάξῃ,
shall do and teach) The same order of words occurs in Act 1:1.—ποιήσῃ,
shall do them, sc. all; for it is not lawful to break or neglect even
one of them.—οὗτος, this man, he) A pronoun used emphatically. Comp.
with this use of οὗτος, ch. Mat 7:21 (Latin Version[192]); Luk 9:24;
Joh 7:18.—μέγας, great) All the commandments are of great account to
him, especially in their full compass[193] (see Mat 5:18); therefore
he shall be called great.