The Phillies missed the boat on LA signings in the past.
Last year, they probably couldn't have spent a large additional allocation, who was available (i.e. wasn't locked up in advance).
They signed a large number of guys, and spent up to their 5% overage.
Given they traded for allocations in the past, I'd be surprised they didn't test the waters.
Next year it should be easier to trade for allocations, a number of teams are limited to $300K signings and might find more effective to trade allocations for prospects, but even then, they're gonna want real prospects, since instead of trading for marginal prospects they could just sign 4 guys for a $1M total. So it's going to be a tough allocation v opportunity cost decision.
I'm not against hitting the FA market next year or the year after (though given this season, 2019 probably makes more sense), I just don't think we have a shot at the top FAs (I wouldn't sign with the Phillies if I could go to Hollywood and sleep with the stars), and I don't want to pay $30M a year for a 31 or 32 year old pitcher on a 6-7 year deal (see Lee, Halladay, et al). But each year there are a half dozen FAs who are solid starters who sign fairly reasonable deals that won't cripple the team going forward. It's just a matter of identify the right guy at the right position and closing the deal.
Trading for a bad contract is also a good use of money, you can get a solid player, get his team to throw in some money and a prospect to boot by taking that contract off their hands (i.e. a 2-3 WAR player making $25M with 2-3 years left on his contract).
But we're not going to spend our way into contention, you still have to do it the old fashioned way, develop players and make good trades.