Maybe, the only problems with this coming back of raids are:
the frequency: 2 per day might be too much, especially because raids, attacking undeveloped ports, are presently focusing on Nations in redevelopment. To be noted that Denmark/Norge suffered more raids since implementation than RU, more than SWE, more than GB, and this is a real pain for this small nation compared to the 3 biggest ones, because this almost cancelled DK/N efforts to make RVR. If players fight NPC's, they can't fight Players. Energy, time and resources placed in NPC Raid defense is lost for port development. And if a port is taken, it has to be redeveloped from grass-root.
NPC raids are attacking undeveloped ports. Nations with big populations will easily develop ports on the frontiers. The other ones can stay undeveloped and even undefended when attacked, because they cannot be taken by any other faction. As a recent example, Arcas, but any of the dozens of port from Selam to Vera-Cruz, La Nouvelle-Orléans down to Gasparilla (except the four ones around El Rancho) would give similar result. To be compared to Bimini, attacked this morning at a time when almost no DK player is in game, and on the frontier with RU and US.
If a rule is set to prevent repetitive attacks on the same nation (I know that this is not announced), this will lead to more pressure on smaller nations: the number of ports that can be attacked by Raiders would be devided by two as soon as RU was attacked the day before, increasing pressure on smaller factions.
Bigger BR by NPC's, tremendously high crew on raiders are no problems as soon as defenders can sink traders first. But yes, this makes raids really dangerous for small factions who cannot lose ports (the biggest can lose most ports at no risk).
However and up to now, I feel more concerned by "oblligation" to attack HDF Fleets for flags and loot than by return of NPC raids. Clearly, the addition of these two obligations reduced my PVP time to almost zero. Not a single PVP kill in July so far. I spend all my playing time in PVE (Raids and HDF).
In last HDF battle I made, I was obliged to go afk during some time during the battle: I was so bored that I was about to surrender to NPC, to shorten my suffering . I stayed afk some time, making something fun out of the game for some minutes, then I could go back and finish this over-boring-pseudo-battle. To be noted that we were originally planning to make 2 HDF hunts, but after the 1st one, all players decided to go back to port: HDF did reach the "ad nauseam" level. To increase our de-motivation, we got no flag in spite of having successfully sunk all HDF ships.
Another player went afk as soon as we went on Open World, even not noticing that he got re attacked by another HDF on the way back. Other players around did not enter in this second fight. Only the 3 ones in this battle stayed in, up to the moment when every one can safely leave (the afk player came back after 10 mins). As a resume, we were in battle with enough players around to fight this HDF fleet, but the consensual decision (just everyone agreeing on this), was just to run out, in spite of having the numbers and the ships to do the fight. We were all totally demotivated.
So maybe, two battles per day, that would preferably spawn on the same reconstructing nation are too much.
Taking into account my personal experience in Denmark/Norway, I can't see how Spain (as an example) can come back from the poor present status (with regards to Spanish players who tried "something" that did not give proper results, this is another question).