No, you could use 'appear' here in English, but it implies that it was an unexpected event, and the use of the simple present tense in this context makes it sound like you're speaking of an event from a third-person perspective.
The key difference here is that 'arrive' can be future tense without an accessory phrase (you don't need 'will arrive') when talking about an event that it is known will happen, while 'appear' needs an accessory phrase to make it future tense even if it is known it will happen. This means that using 'arrive' here could either mean the arrival is occurring right now (in which case it also sounds like a third-person perspective of the event) or that it is known to some degree of certainty that it will happen within the stated time-frame (in which case it could be any perspective, not just third-person).
In American English, if guests "appear" it is a total surprise. If they come when expected, they "arrive" or "show up." The quality of the American English translations has deteriorated considerably since the change. Some are just plain wrong and while some may be defended with help of a dictionary, they are things we NEVER say.
I would actually say that "appear" suggests the arrival in an unexpected way at an undetermined time, "show up" signifies arriving in a traditional way at an undetermined time, and "arrive" would be a traditional arrival at a planned time. So, we may say these things, bùt they would indicate different types of the same encounter.
For the case of 'arrive' versus 'appear' in English, the key difference is that 'arrive' implies that the subject is moving in some way to get to the place they arrive at, while 'appear' implies a sudden event that does not inherently involve motion. Additionally, 'arrive' does not need an accessory phrase to talk about the future ('I arrive at noon.' could mean that I will arrive at noon or that I am currently arriving at noon), but 'appear' usually does need an accessory phrase to be future tense.
I'm still not 100% certain about the connotations and implications of the Swedish phrases myself though. At least 'dyker upp' seems to sometimes be used differently from the English 'appear' (such as in the sentence this comments section is for, most native English speakers would use 'arrive' here, not 'appear' unless the guests' arrival was truly unexpected).
It’s an essential part of the verb phrase here.
‘att dyka upp’ is a phrasal verb (more specifically a particle verb, because the preposition ‘upp’ has no complement), which means it consists of more than one word and only has it’s complete meaning when taken as a whole. ‘att dyka’ by itself is ‘to dive’ or ‘to submerge’. The addition of ‘upp’ changes the meaning completely to refer to something appearing or possibly arriving.
English has phrasal verbs as well, though many native speakers don’t really think of them as being a verb phrase instead of just a verb and something else. Examples include ‘to look after’ (a prepositional verb, which if translated literally, is actually a phrasal verb in Swedish too, though the meaning is different), ‘to give in’, or ‘to bring up’ (both of which are particle verbs like ‘att dyka upp’).