I'm not going to bother arguing the actual wording of the two features as people have done this enough. Instead, I will argue about the following-- does the weapon-using Sorcerer become overpowered by having the possibility of twice per day making all their weapon attacks for 1 minute have Advantage? This is the actual worry about the combination of Innate Sorcery and True Strike. Does using these two features working in conjunction cause the weapon-using Sorcerer to be overpowered compared to other weapon-using characters?
Well... let's look at other classes wherein they can get multiple attempts at weapon attacking with Advantage:
- Barbarians starting at 2nd level can make every attack they take with Advantage because of Reckless Attack, however they receive attacks back with Advantage as well. But starting at 5th level the Barbarian gets to attack twice each round, something the Innate True Striking Sorcerer cannot. So they get many more attacks with Advantage than the Sorcerer, but they receive a punishment for doing so.
- Oath of Vengeance Paladins have two uses of Channel Divinity per day starting at 3rd level, and that allows them to make all attacks with Advantage for 1 minute (same duration as the Sorcerer). They also get Extra Attack at 5th level like the Barbarian, so in both cases the Paladin and Barbarian are making twice as many weapon attacks with Advantage as an Innate True Striking Sorcerer does, once those classes hit 5th level.
- The Innate True Striking Sorcerer is the only one of the three with the ability to make every attack have Advantage starting at 1st level... but due to the fact they have to cast a spell to do so, they only ever can make a single attack with Advantage per round as per the rules of the spell (even if they acquired Extra Attack some other time later via multiclassing.)
So the question we must ask is whether the Sorcerer gaining the ability to weapon attack with Advantage at 1st level (rather than 2nd for the Barbarian and 3rd for the Paladin) but only getting one attack per round to do so... makes them overpowered compared to the Barbarian and Paladin who will get to attack twice each round with Advantage starting at 5th level? To me, I would say No. They are not more powerful than Barbarians and Paladins because that one slight bonus (gaining the ability one level or two levels earlier) is more than offset by the fact they won't ever get to attack twice per round with it.
Now I'm sure some people would also want to compare the weapon-using Sorcerer to its natural comparable rival, the weapon-using Warlock, to see if the Sorcerer is overpowered compared to it as well. Well, the weapon-using Warlock would take Pact of the Blade at 1st level, and thus will use Charisma for attacks and damage the same as the Sorcerer (with True Strike) would. But they would not get to make their attacks with Advantage like the Sorcerer could. However... at 2nd level with the selection of the Eldritch Smite invocation, they can add an extra 1d8 damage per slot level twice per short rest (or more if they take 1 minute to regain some slots via Magical Cunning)... and at 5th level with Thirsting Blade they can attack twice per round, and three times per round at 12th level Devouring Blade.
So this question is whether the Sorcerer attacking once per round with Advantage is overpowered compared to a Pact of the Blade Warlock who won't attack with Advantage, but will have the opportunity to add many multiple d8s of damage to each hit when they make them, plus the opportunity to attack twice / three times per round down the line. To me? Again, I would say No. They are not more powerful than a Pact of the Blade Warlock.
So what does that mean? It means that at least to me... there is no reason balance-wise to not allow the combination of Innate Sorcery and True Strike work together for a weapon-using Sorcerer. So I wouldn't even bother waiting around for some final person at WotC to explain the common English Ruled-As-Intended version they were trying to get across... and instead just allow it from the go. It just isn't powerful enough to feel the need to not allow it, or waste my time waiting for someone from WotC to get around to telling me its okay.